lpc1768: turn down the jtag clock

Tests should that it needs to be as low as 100kHz to be
stable.

Signed-off-by: Øyvind Harboe <oyvind.harboe@zylin.com>
__archive__
Øyvind Harboe 2010-08-13 12:59:36 +02:00
parent dce422516a
commit f60a2390cc
1 changed files with 9 additions and 7 deletions

View File

@ -47,16 +47,18 @@ set _FLASHNAME $_CHIPNAME.flash
flash bank $_FLASHNAME lpc2000 0x0 0x80000 0 0 $_TARGETNAME \
lpc1700 $_CCLK calc_checksum
# JTAG clock should be CCLK/6 (unless using adaptive clocking)
# CCLK is 4 MHz after reset, and until board-specific code (like
# a reset-init handler) speeds it up.
#
# Although rclk "appears to work", it turns out that this yields
# 4MHz whereas the "correct" rate is CCLK/6, which is not what
# you get with rclk.
jtag_khz [ expr 4000 / 6 ]
#
# Also, crank down the frequency further as we're running of an
# RC oscillator instead of crystal.
#
# Setting up XTAL in the reset-init sequence could be worth
# the effort if you need to program the flash which is pretty
# big on these devices.
#
jtag_khz 100
$_TARGETNAME configure -event reset-init {
# Do not remap 0x0000-0x0020 to anything but the flash (i.e. select