riscv-openocd/tcl/board/mcb1700.cfg

# Keil MCB1700 PCB with 1768
# 
# Reset init script sets it to 100MHz
set CCLK 100000

source [find target/lpc17xx.cfg]

global MCB1700_CCLK
set MCB1700_CCLK $CCLK

$_TARGETNAME configure -event reset-start {
	# Start *real slow* as we do not know the
    # state the boot rom left the clock in
	adapter speed 10
}

# Set up 100MHz clock to CPU
$_TARGETNAME configure -event reset-init {
    # PLL0CON: Disable PLL
	mww 0x400FC080 0x00000000
    # PLLFEED
	mww 0x400FC08C 0x000000AA
    # PLLFEED
	mww 0x400FC08C 0x00000055

    # CCLK=PLL/4 (=100 MHz)
	mww 0x400FC104 0x00000003
    # CLKSRCSEL: Clock source = internal RC oscillator
	mww 0x400FC10C 0x00000000

    # PLL0CFG: M=50,N=1 -> PLL=400 MHz
	mww 0x400FC084 0x00000031
    # PLLFEED
	mww 0x400FC08C 0x000000AA
    # PLLFEED
	mww 0x400FC08C 0x00000055

	# PLL0CON: Enable PLL
	mww 0x400FC080 0x00000001
    # PLLFEED
	mww 0x400FC08C 0x000000AA
    # PLLFEED
	mww 0x400FC08C 0x00000055

	sleep 50

    # PLL0CON: Connect PLL
	mww 0x400FC080 0x00000003
    # PLLFEED
	mww 0x400FC08C 0x000000AA
    # PLLFEED
	mww 0x400FC08C 0x00000055

	# Dividing CPU clock by 8 should be pretty conservative
	#
	# 
	global MCB1700_CCLK
	adapter speed [expr $MCB1700_CCLK / 8]

	# Do not remap 0x0000-0x0020 to anything but the flash (i.e. select
	# "User Flash Mode" where interrupt vectors are _not_ remapped,
	# and reside in flash instead).
	#
	# See Table 612. Memory Mapping Control register (MEMMAP - 0x400F C040) bit description
	# Bit Symbol Value Description Reset
	# value
	# 0 MAP Memory map control. 0
	# 0 Boot mode. A portion of the Boot ROM is mapped to address 0.
	# 1 User mode. The on-chip Flash memory is mapped to address 0.
	# 31:1 - Reserved. The value read from a reserved bit is not defined. NA
	#
	# http://ics.nxp.com/support/documents/microcontrollers/?scope=LPC1768&type=user

	mww 0x400FC040 0x01
}