FreeCalypso > hg > freecalypso-tools

annotate doc/Target-utils @ 521:6604403aa212

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
doc/Target-utils: checking in unfinished document
author Mychaela Falconia <falcon@freecalypso.org>
date Thu, 06 Jun 2019 06:38:46 +0000
parents
children aa4f70e36cbd
Ignore whitespace changes - Everywhere: Within whitespace: At end of lines:
rev   line source
521
6604403aa212 doc/Target-utils: checking in unfinished document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1 FreeCalypso target-utils suite
6604403aa212 doc/Target-utils: checking in unfinished document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
2 ==============================
6604403aa212 doc/Target-utils: checking in unfinished document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
3
6604403aa212 doc/Target-utils: checking in unfinished document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
4 We have a suite of standalone programs and specialized code pieces that run on
6604403aa212 doc/Target-utils: checking in unfinished document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
5 the Calypso ARM7 processor, but are not regular operational phone or modem
6604403aa212 doc/Target-utils: checking in unfinished document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
6 firmware; this suite of code bits is called target-utils, maintained and
6604403aa212 doc/Target-utils: checking in unfinished document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
7 distributed together with FreeCalypso host tools. The primary reason for the
6604403aa212 doc/Target-utils: checking in unfinished document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
8 coupling between FC host tools and target-utils is that the target-utils suite
6604403aa212 doc/Target-utils: checking in unfinished document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
9 provides the loadagent target program for fc-loadtool and fc-xram host tools,
6604403aa212 doc/Target-utils: checking in unfinished document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
10 as well as compalstage code pieces needed for operating on Compal phones.
6604403aa212 doc/Target-utils: checking in unfinished document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
11
6604403aa212 doc/Target-utils: checking in unfinished document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
12 Most programs in the target-utils suite are meant to execute out of RAM
6604403aa212 doc/Target-utils: checking in unfinished document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
13 (specifically, the Calypso chip's internal RAM or IRAM for short), loaded and
6604403aa212 doc/Target-utils: checking in unfinished document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
14 run via fc-iram or fc-compalram - they are not meant to be flashed. As of this
6604403aa212 doc/Target-utils: checking in unfinished document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
15 writing, the following run-from-RAM programs are available:
6604403aa212 doc/Target-utils: checking in unfinished document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
16
6604403aa212 doc/Target-utils: checking in unfinished document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
17 buzplayer Player for buzzer melodies, used by fc-buzplay
6604403aa212 doc/Target-utils: checking in unfinished document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
18 c139explore Mot C139 hardware exploration program
6604403aa212 doc/Target-utils: checking in unfinished document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
19 calversion Calypso version ID tool, primarily for the DSP ROM version
6604403aa212 doc/Target-utils: checking in unfinished document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
20 helloapp Hello-world program
6604403aa212 doc/Target-utils: checking in unfinished document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
21 loadagent Flash manipulation and XRAM loading agent
6604403aa212 doc/Target-utils: checking in unfinished document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
22 pirexplore Pirelli DP-L10 hardware exploration program
6604403aa212 doc/Target-utils: checking in unfinished document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
23 simtest Low-level exerciser for the SIM interface hardware
6604403aa212 doc/Target-utils: checking in unfinished document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
24
6604403aa212 doc/Target-utils: checking in unfinished document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
25 Aside from c139explore which is built as a binary to be loaded via fc-compalram
6604403aa212 doc/Target-utils: checking in unfinished document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
26 (Compal's bootloader protocol), all of the above programs are built as S-record
6604403aa212 doc/Target-utils: checking in unfinished document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
27 images to be loaded via fc-iram. Once loaded via the respective serial code
6604403aa212 doc/Target-utils: checking in unfinished document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
28 download protocol, each of the listed programs runs interactively, listening
6604403aa212 doc/Target-utils: checking in unfinished document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
29 for and executing commands given over the serial port. The specific set of
6604403aa212 doc/Target-utils: checking in unfinished document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
30 available commands is different for each program as relevant to its function,
6604403aa212 doc/Target-utils: checking in unfinished document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
31 but the command framework is common across the target-utils suite. The command
6604403aa212 doc/Target-utils: checking in unfinished document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
32 interface is text-based, such that each program can be driven manually by a
6604403aa212 doc/Target-utils: checking in unfinished document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
33 human operator once fc-iram or fc-compalram has dropped into the tty pass-thru
6604403aa212 doc/Target-utils: checking in unfinished document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
34 mode, but this same text-based command interface can also be driven by other
6604403aa212 doc/Target-utils: checking in unfinished document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
35 programs: fc-loadtool and fc-xram drive loadagent, and fc-buzplay drives
6604403aa212 doc/Target-utils: checking in unfinished document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
36 buzplayer.
6604403aa212 doc/Target-utils: checking in unfinished document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
37
6604403aa212 doc/Target-utils: checking in unfinished document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
38 Code architecture and execution environment
6604403aa212 doc/Target-utils: checking in unfinished document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
39 ===========================================
6604403aa212 doc/Target-utils: checking in unfinished document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
40
6604403aa212 doc/Target-utils: checking in unfinished document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
41 Our target-utils suite is built with the GNU toolchain (gcc+binutils), not TI's
6604403aa212 doc/Target-utils: checking in unfinished document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
42 proprietary TMS470 compiler. Because all of target-utils are meant to run out
6604403aa212 doc/Target-utils: checking in unfinished document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
43 of IRAM rather than flash or XRAM, we compile all code in ARM mode (not Thumb),
6604403aa212 doc/Target-utils: checking in unfinished document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
44 and we build without interworking support (no -mthumb-interwork): the ARMv4T
6604403aa212 doc/Target-utils: checking in unfinished document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
45 architecture implemented by the ARM7TDMI core in the Calypso does not support
6604403aa212 doc/Target-utils: checking in unfinished document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
46 penalty-free ARM/Thumb interworking, thus ARM-only code without interworking
6604403aa212 doc/Target-utils: checking in unfinished document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
47 support is the most efficient option for execution out of IRAM.
6604403aa212 doc/Target-utils: checking in unfinished document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
48
6604403aa212 doc/Target-utils: checking in unfinished document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
49 Selection of UART for communication
6604403aa212 doc/Target-utils: checking in unfinished document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
50 ===================================
6604403aa212 doc/Target-utils: checking in unfinished document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
51
6604403aa212 doc/Target-utils: checking in unfinished document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
52 All target-utils programs are interactive, listening for text commands given
6604403aa212 doc/Target-utils: checking in unfinished document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
53 over a serial port. But which UART? The Calypso chip has two UARTs, called
6604403aa212 doc/Target-utils: checking in unfinished document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
54 MODEM and IrDA in the chip docs - which of the two should be used for host
6604403aa212 doc/Target-utils: checking in unfinished document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
55 communication? The answer is a trick original to FreeCalypso: most of our
6604403aa212 doc/Target-utils: checking in unfinished document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
56 target-utils programs that are meant to be loaded via fc-iram expect to be
6604403aa212 doc/Target-utils: checking in unfinished document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
57 loaded specifically via the Calypso boot ROM and not in some other way, and
6604403aa212 doc/Target-utils: checking in unfinished document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
58 they look at some of the IRAM variables left behind by the boot ROM code. The
6604403aa212 doc/Target-utils: checking in unfinished document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
59 boot ROM listens on both UARTs for an interrupt-boot sequence, and once it
6604403aa212 doc/Target-utils: checking in unfinished document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
60 receives that sequence on one of the UARTs, it remembers which UART it was and
6604403aa212 doc/Target-utils: checking in unfinished document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
61 uses that same UART for the rest of the serial code download protocol. We read
6604403aa212 doc/Target-utils: checking in unfinished document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
62 that same variable set by the boot ROM, which depends on the boot ROM version.
6604403aa212 doc/Target-utils: checking in unfinished document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
63 To handle different Calypso boot ROM versions, we read the 16-bit word at 0x1FFE
6604403aa212 doc/Target-utils: checking in unfinished document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
64 (the last 16 bits of the boot ROM image) where TI put the boot ROM version
6604403aa212 doc/Target-utils: checking in unfinished document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
65 number, and we support boot ROM versions 0200 (Calypso C05 rev B silicon) and
6604403aa212 doc/Target-utils: checking in unfinished document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
66 0300 (Calypso C035 silicon). Most target-utils programs won't work (will fail
6604403aa212 doc/Target-utils: checking in unfinished document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
67 to select the UART for communication) if the boot ROM is some unsupported
6604403aa212 doc/Target-utils: checking in unfinished document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
68 version or missing altogether, or if the boot ROM is there, but didn't do the
6604403aa212 doc/Target-utils: checking in unfinished document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
69 loading.
6604403aa212 doc/Target-utils: checking in unfinished document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
70
6604403aa212 doc/Target-utils: checking in unfinished document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
71 The exceptions are as follows:
6604403aa212 doc/Target-utils: checking in unfinished document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
72
6604403aa212 doc/Target-utils: checking in unfinished document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
73 * c139explore always uses the MODEM UART as appropriate for Mot C139;
6604403aa212 doc/Target-utils: checking in unfinished document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
74
6604403aa212 doc/Target-utils: checking in unfinished document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
75 * flash-boot-test (a flashable program described later in this article) always
6604403aa212 doc/Target-utils: checking in unfinished document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
76 uses the IrDA UART;
6604403aa212 doc/Target-utils: checking in unfinished document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
77
6604403aa212 doc/Target-utils: checking in unfinished document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
78 * helloapp is built in 3 versions: helloapp-bootrom.srec, helloapp-irda.srec
6604403aa212 doc/Target-utils: checking in unfinished document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
79 and helloapp-modem.srec. The first version depends on the boot ROM like
6604403aa212 doc/Target-utils: checking in unfinished document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
80 other programs, the other two versions are built as fixed-IrDA or fixed-MODEM.
6604403aa212 doc/Target-utils: checking in unfinished document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
81
6604403aa212 doc/Target-utils: checking in unfinished document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
82 Other boot ROM and fc-iram dependencies
6604403aa212 doc/Target-utils: checking in unfinished document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
83 =======================================
6604403aa212 doc/Target-utils: checking in unfinished document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
84
6604403aa212 doc/Target-utils: checking in unfinished document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
85 There are two other ways in which target-utils programs that are meant to be
6604403aa212 doc/Target-utils: checking in unfinished document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
86 loaded via fc-iram depend on the Calypso boot ROM:
6604403aa212 doc/Target-utils: checking in unfinished document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
87
6604403aa212 doc/Target-utils: checking in unfinished document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
88 1) The Calypso gets its clock input from the RF section of the GSM device, and
6604403aa212 doc/Target-utils: checking in unfinished document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
89 the RF block can feed either 13 MHz or 26 MHz to the Calypso - some GSM RF
6604403aa212 doc/Target-utils: checking in unfinished document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
90 transceiver chips require 13 MHz (TI Clara), others require 26 MHz (TI Rita
6604403aa212 doc/Target-utils: checking in unfinished document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
91 and Silabs Aero II), yet others can work with either clock (Silabs Aero+),
6604403aa212 doc/Target-utils: checking in unfinished document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
92 and some use a 26 MHz crystal but have the option of feeding either 13 or
6604403aa212 doc/Target-utils: checking in unfinished document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
93 26 MHz to the Calypso (Aero II). The Calypso initially boots without knowing
6604403aa212 doc/Target-utils: checking in unfinished document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
94 what clock frequency it is running at, but then it needs to be told via a
6604403aa212 doc/Target-utils: checking in unfinished document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
95 register setting what the input clock frequency is, so that all peripherals
6604403aa212 doc/Target-utils: checking in unfinished document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
96 (both GSM-specific and general-purpose) always run at 13 MHz.
6604403aa212 doc/Target-utils: checking in unfinished document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
97
6604403aa212 doc/Target-utils: checking in unfinished document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
98 When the Calypso boot process is interrupted and diverted to serial code
6604403aa212 doc/Target-utils: checking in unfinished document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
99 download in the boot ROM, the boot ROM code autodetects whether the CLKTCXO
6604403aa212 doc/Target-utils: checking in unfinished document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
100 input runs at 13 MHz or 26 MHz (it tries both register bits settings until
6604403aa212 doc/Target-utils: checking in unfinished document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
101 the serial '<' characters sent by the host at 19200 baud are received
6604403aa212 doc/Target-utils: checking in unfinished document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
102 correctly), and if the CLKTCXO input is 26 MHz, the VCLKOUT_DIV2 bit is set
6604403aa212 doc/Target-utils: checking in unfinished document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
103 in the FFFF:FD02 register. Most of our target-utils programs have no hard-
6604403aa212 doc/Target-utils: checking in unfinished document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
104 coded knowledge of the 13 MHz vs. 26 MHz board hardware configuration and
6604403aa212 doc/Target-utils: checking in unfinished document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
105 rely on the Calypso boot ROM to set the division control bits in the
6604403aa212 doc/Target-utils: checking in unfinished document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
106 FFFF:FD02 register correctly for the autodetected clock.
6604403aa212 doc/Target-utils: checking in unfinished document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
107
6604403aa212 doc/Target-utils: checking in unfinished document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
108 2) The boot ROM allows the serial download host (fc-iram in our case) to
6604403aa212 doc/Target-utils: checking in unfinished document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
109 configure the Calypso DPLL, allowing the ARM7 core to run at its maximum
6604403aa212 doc/Target-utils: checking in unfinished document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
110 frequency of 52 MHz on Calypso C035 or 39 MHz on the older Calypso C05
6604403aa212 doc/Target-utils: checking in unfinished document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
111 silicon. None of our target-utils programs do their own DPLL setup, instead
6604403aa212 doc/Target-utils: checking in unfinished document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
112 they run with whatever they were booted with - therefore, in order for the
6604403aa212 doc/Target-utils: checking in unfinished document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
113 IRAM programs to run at their intended fastest speed, the correct -h option
6604403aa212 doc/Target-utils: checking in unfinished document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
114 needs to be given to fc-iram, selecting a hardware parameter file with the
6604403aa212 doc/Target-utils: checking in unfinished document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
115 right pll-config setting.
6604403aa212 doc/Target-utils: checking in unfinished document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
116
6604403aa212 doc/Target-utils: checking in unfinished document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
117 Delay loop timing
6604403aa212 doc/Target-utils: checking in unfinished document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
118 =================
6604403aa212 doc/Target-utils: checking in unfinished document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
119
6604403aa212 doc/Target-utils: checking in unfinished document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
120 There are a few places in target-utils where a delay of some specific duration
6604403aa212 doc/Target-utils: checking in unfinished document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
121 needs to be inserted. In most cases the requirement is for a certain minimum
6604403aa212 doc/Target-utils: checking in unfinished document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
122 delay, with more delay time being harmless except for inefficiency, but there
6604403aa212 doc/Target-utils: checking in unfinished document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
123 is one case (SPCA552E chip initialization in pirexplore) where the delay
6604403aa212 doc/Target-utils: checking in unfinished document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
124 requirement is strict: if the delays are too short or too long, the LCD doesn't
6604403aa212 doc/Target-utils: checking in unfinished document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
125 work. In target-utils all of these delays are implemented with CPU-cycle-count
6604403aa212 doc/Target-utils: checking in unfinished document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
126 delay loops that are calibrated at software design time; if the code runs out
6604403aa212 doc/Target-utils: checking in unfinished document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
127 of IRAM and the ARM7 core runs at 52 MHz, the delays will be exactly as
6604403aa212 doc/Target-utils: checking in unfinished document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
128 designed, otherwise they will be longer. In the case of pirexplore the strict
6604403aa212 doc/Target-utils: checking in unfinished document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
129 timing requirement is satisfied by loading and running the program via fc-iram
6604403aa212 doc/Target-utils: checking in unfinished document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
130 -h pirelli, resulting in the correct 52 MHz clock configuration; in all other
6604403aa212 doc/Target-utils: checking in unfinished document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
131 cases running at a frequency below 52 MHz or running out of flash (the
6604403aa212 doc/Target-utils: checking in unfinished document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
132 flash-boot-test special case) produces longer-than-needed delays.