ARM UART0 input output. LPC2138 What am I doing wrong. [duplicate]
问题 This question already has an answer here : ARM Assembly Language uART0 Input Output, What am I doing wrong. (1 answer) Closed 5 years ago . read_character LDR r0, =0xE000C014 LDRB r1, [r0] BIC r1, r1, #0xFFFFFFF0 CMP r1, 0 BEQ read_character LDR r6, =r1 LDR r2, [r6] output_character LDR r0, =0xE000C014 LDRB r1, [r0] ORR r1, r1, #0x00000010 MOV r1, r1, LSR #1 CMP r1, 0 BEQ output_character LDR r6, =r1 STR r2, [r6] What am I doing wrong? My motive is to create a routine to take in the character