hello,
Now, I write uart assemble code during the boot of ls1021atwr. But the uart don't ouput anything, I don't know any? do anyone have idea?
The following assemble code:
UART_LCR=0x21C0503
UART_DLB=0x21C0500
UART_DMB=0x21C0501
UART_SND=0x21c0500
UART_IER=0x21c0501
UART_MCR=0x21c0504
UART_FCR=0x21c0502
LOOP1:
ldr r3, =0x21c0505
ldr r4, [r3]
tst r4, #0x40
bne LOOP1
ldr r0, =(UART_IER)
ldr r1, =0x00
str r1, [r0]
ldr r0, =(UART_MCR)
ldr r1, =0x03
str r1, [r0]
ldr r0, =(UART_FCR)
ldr r1, =0x07
str r1, [r0]
/*
* setting line control register and
* setting serial baud,including DLB and DMB
*/
ldr r0, =(UART_LCR)
ldr r1, =0X83
str r1, [r0]
ldr r0, =0XA3
ldr r1, =(UART_DLB)
str r0, [r1]
ldr r0, =0X00
ldr r1, =(UART_DMB)
str r0, [r1]
ldr r0, =(UART_LCR)
ldr r1, =0X03
str r1, [r0]
/*
* send data to send buffer
*/
mov r0, #0x24
ldr r1, =(UART_SND)
str r0, [r1]
mov r3, #100
LOOP2:
sub r3, r3, #1
cmp r3, #0
bne LOOP2
