Hi! I'm new on ARM. I'm using uVision 4.71 with j-link + LPC1343 cortex-m3 running following code:
movw r0,#0x0001 ;working
ldr r1,=0x4004400c ;working
str r0, [r1, #0] ;not working
movw r0,#0x00ff ;working
ldr r1,=0x50008000 ;working
str r0, [r1] ;working
movw r0,#0x00aa ;working
ldr r1,=0x50003FFC ;working
movw r0,#0x000f ;working
ldr r1,=0x50038000 ;working
movw r0,#0x0002 ;working
ldr r1,=0x40044084 ;working
str r0, [r1] ;not working
movw r0,#0x0000 ;working
ldr r1,=0x50033ffc ;working
seems that addresses = 0x4004xxxx have no permission to writes Can anybody help me?
Check the documentation of your microcontroller again.
According to user manual UM10375, Section 7.4.32, address 0x4004 4084 is IOCON_PIO3_0.
The only valid values you can store in Bits 2:0 are 0 or 1 (and 1 is not applicable to all parts). If you are using code written by someone else, make sure that it is designed to run on an LPC1343.
It's done! By default, the bit 16 in SYSAHBCLKCTRL(0x40048080) in reset is zero, disabling clocks to IOCON block. So, i put the following code at start of program to solve my problem:
movw r1,#0x8080
movt r1,#0x4004
ldr r0,[r1]
orr r0,#0x10000
str r0,[r1]