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fix(serial): now returning read status codes from polled char input

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This commit is contained in:
Gale Misery Faraday
2025-09-26 13:52:31 -05:00
parent a019c37755
commit 53add429a9
1 changed files with 6 additions and 5 deletions
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11
src/serial.s
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@@ -85,14 +85,15 @@ END@
; Reads a char in polled mode non-FIFO mode (INITUART state).
; A: Filled with char from RX buffer or NUL ($00) if no char is ready
; B: Filled with LSR status codes masked with $9F
PINCHAR
lda UART_LSR ; See if a char is ready
ldb UART_LSR ; See if a char is ready
; Mask of possible UART error codes | data ready flag ($9F)
anda #(UARTF_LSR_DR|UARTF_LSR_OE|UARTF_LSR_PE|UARTF_LSR_FE|UARTF_LSR_BI|UARTF_LSR_FIFO)
bita #UARTF_LSR_DR
andb #(UARTF_LSR_DR|UARTF_LSR_OE|UARTF_LSR_PE|UARTF_LSR_FE|UARTF_LSR_BI|UARTF_LSR_FIFO)
bitb #UARTF_LSR_DR ; Check for char
beq NOCHAR@
lda UART_RBR ; Pull char from RX buffer
lda UART_RBR ; Pull char from RX buffer
rts
NOCHAR@
clra ; Fill A with '\0'.
clra ; Fill A with '\0'.
rts