Files
aqhomecontrol/avr/modules/uart_hw/lowlevel_uart1.asm

132 lines
3.7 KiB
NASM

; ***************************************************************************
; copyright : (C) 2025 by Martin Preuss
; email : martin@libchipcard.de
;
; ***************************************************************************
; * This file is part of the project "AqHome". *
; * Please see toplevel file COPYING of that project for license details. *
; ***************************************************************************
.cseg
; ---------------------------------------------------------------------------
; @routine UART_HW_Uart1_StartRx @global
;
; @clobbers none
UART_HW_Uart1_StartRx:
lds r16, UCSR1B
sbr r16, (1<<RXCIE1) ; enable RX complete interrupt
sbr r16, (1<<RXEN1) ; enable receive
sts UCSR1B, r16
ret
; @end
; ---------------------------------------------------------------------------
; @routine UART_HW_Uart1_StopRx @global
;
; @clobbers none
UART_HW_Uart1_StopRx:
lds r16, UCSR1B
cbr r16, (1<<RXCIE1) ; disable RX complete interrupt
cbr r16, (1<<RXEN1) ; disable receive
sts UCSR1B, r16
ret
; @end
; ---------------------------------------------------------------------------
; @routine UART_HW_Uart1_StartTx @global
;
; @param Y pointer to interface data in SRAM (see @ref UART_HW_IFACE_OFFS_STATE)
; @clobbers none
UART_HW_Uart1_StartTx:
lds r16, UCSR1B
sbr r16, (1<<UDRIE1) ; enable TX data register empty interrupt
sbr r16, (1<<TXEN1) ; enable transceive
sts UCSR1B, r16
ret
; @end
; ---------------------------------------------------------------------------
; @routine UART_HW_Uart1_StopTx @global
;
; @param Y pointer to interface data in SRAM (see @ref UART_HW_IFACE_OFFS_STATE)
; @clobbers none
UART_HW_Uart1_StopTx:
lds r16, UCSR1B
cbr r16, (1<<UDRIE1) ; disable TX data register empty interrupt
cbr r16, (1<<TXEN1) ; disable transceive
sts UCSR1B, r16
ret
; @end
; ---------------------------------------------------------------------------
; @routine UART_HW_Uart1_RxCharIsr @global
;
; @param Y pointer to interface data in SRAM (see @ref UART_HW_IFACE_OFFS_MODE)
; @clobbers R16 (R17, R18, X)
UART_HW_Uart1_RxCharIsr:
in r16, UCSR1A ; check for errors
andi r16, (1<<FE1) | (1<<DOR1) | (1<<UPE1)
breq UART_HW_Uart1_RxCharIsr_recv
ldd r16, Y+UART_HW_IFACE_OFFS_STATUS
ori r16, UART_HW_STATUS_HWERR
std Y+UART_HW_IFACE_OFFS_STATUS, r16
rjmp UART_HW_Uart1_RxCharIsr_end
UART_HW_Uart1_RxCharIsr_recv:
lds r16, UCSR1A
sbrs r16, RXC1
rjmp UART_HW_Uart1_RxCharIsr_end ; no data
lds r16, UDR1
rcall UART_HW_InterfaceWriteToReadBuffer ; (R17, R18, X)
brcs UART_HW_Uart1_RxCharIsr_end
ldd r16, Y+UART_HW_IFACE_OFFS_STATUS ; set overrun error
ori r16, UART_HW_STATUS_OVERRUN
std Y+UART_HW_IFACE_OFFS_STATUS, r16
UART_HW_Uart1_RxCharIsr_end:
ret
; @end
; ---------------------------------------------------------------------------
; @routine UART_HW_Uart1_TxCharIsr @global
;
; @param Y pointer to interface data in SRAM (see @ref UART_HW_IFACE_OFFS_MODE)
; @clobbers R16, (R17, R18, X)
UART_HW_Uart1_TxCharIsr:
lds r16, UCSR1A
sbrs r16,UDRE1
rjmp UART_HW_Uart1_TxCharIsr_end ; not ready
rcall UART_HW_InterfaceReadFromWriteBuffer ; (R17, R18, X)
brcs UART_HW_Uart1_TxCharIsr_send ; no data in buffer
ldd r16, Y+UART_HW_IFACE_OFFS_STATUS ; set underrun error
ori r16, UART_HW_STATUS_UNDERRUN
std Y+UART_HW_IFACE_OFFS_STATUS, r16
rjmp UART_HW_Uart1_TxCharIsr_end
UART_HW_Uart1_TxCharIsr_send:
sts UDR1, r16
UART_HW_Uart1_TxCharIsr_end:
ret
; @end