;
;==================================================================================================
; ASCI DRIVER (Z180 SERIAL PORTS)
;==================================================================================================
;
; CHARACTER DEVICE DRIVER ENTRY
;   A: RESULT (OUT), CF=ERR
;   B: FUNCTION (IN)
;   C: CHARACTER (IN/OUT)
;   E: DEVICE/UNIT (IN)
;
;
ASCI_DISPATCH:
	LD	A,C	; GET DEVICE/UNIT
	AND	$0F	; ISOLATE UNIT
	JP	Z,ASCI0
	DEC	A
	JP	Z,ASCI1
	CALL	PANIC
;
ASCI0:
	LD	A,B	; GET REQUESTED FUNCTION
	AND	$0F	; ISOLATE SUB-FUNCTION
	JP	Z,ASCI0_IN
	DEC	A
	JP	Z,ASCI0_OUT
	DEC	A
	JP	Z,ASCI0_IST
	DEC	A
	JP	Z,ASCI0_OST
	CALL	PANIC
;
;
;
ASCI_INIT:
	; ASCI0
	PRTS("ASCI0: IO=0x$")
	LD	A,CPU_TDR0
	CALL	PRTHEXBYTE
	CALL	PC_COMMA
	LD	A,CPU_RDR0
	CALL	PRTHEXBYTE
	PRTS(" BAUD=$")
	LD	HL,ASCI0BAUD / 10
	CALL	PRTDEC
	PRTC('0')

	LD	A,66H
	OUT0	(CPU_ASEXT0),A
	LD	A,64H
	OUT0	(CPU_CNTLA0),A
	LD	A,Z180_CNTLB0
	OUT0	(CPU_CNTLB0),A

	; ASCI1
	CALL	NEWLINE
	PRTS("ASCI1: IO=0x$")
	LD	A,CPU_TDR1
	CALL	PRTHEXBYTE
	CALL	PC_COMMA
	LD	A,CPU_RDR1
	CALL	PRTHEXBYTE
	PRTS(" BAUD=$")
	LD	HL,ASCI1BAUD / 10
	CALL	PRTDEC
	PRTC('0')

	LD	A,66H
	OUT0	(CPU_ASEXT1),A
	LD	A,64H
	OUT0	(CPU_CNTLA1),A
	LD	A,Z180_CNTLB1
	OUT0	(CPU_CNTLB1),A
	RET
;
;
;
ASCI0_IN:
	CALL	ASCI0_IST
	OR	A
	JR	Z,ASCI0_IN
	IN0	A,(CPU_RDR0)	; READ THE CHAR FROM THE ASCI
	LD	E,A
	RET
;
;
;
ASCI0_IST:
	; CHECK FOR ERROR FLAGS
	IN0	A,(CPU_STAT0)
	AND	70H			; PARITY, FRAMING, OR OVERRUN ERROR
	JR	Z,ASCI0_IST1		; ALL IS WELL, CHECK FOR DATA

	; CLEAR ERROR(S) OR NOTHING FURTHER CAN BE RECEIVED!!!
	IN0	A,(CPU_CNTLA0)
	RES	3,A			; CLEAR EFR (ERROR FLAG RESET)
	OUT0	(CPU_CNTLA0),A

ASCI0_IST1:	; CHECK FOR STAT0.RDRF (DATA READY)
	IN0	A,(CPU_STAT0)		; READ LINE STATUS REGISTER
	AND	$80			; TEST IF DATA IN RECEIVE BUFFER
	JP	Z,CIO_IDLE		; DO IDLE PROCESSING AND RETURN
	XOR	A
	INC	A			; SIGNAL CHAR READY, A = 1
	RET
;
;
;
ASCI0_OUT:
	CALL	ASCI0_OST
	OR	A
	JR	Z,ASCI0_OUT
	LD	A,E
	OUT0	(CPU_TDR0),A
	RET
;
ASCI0_OST:
	IN0	A,(CPU_STAT0)
	AND	$02
	JP	Z,CIO_IDLE		; DO IDLE PROCESSING AND RETURN
	XOR	A
	INC	A			; SIGNAL BUFFER EMPTY, A = 1
	RET
;
;
;
ASCI1:
	LD	A,B	; GET REQUESTED FUNCTION
	AND	$0F	; ISOLATE SUB-FUNCTION
	JR	Z,ASCI0_IN
	DEC	A
	JR	Z,ASCI0_OUT
	DEC	A
	JR	Z,ASCI0_IST
	DEC	A
	JR	Z,ASCI0_OST
	CALL	PANIC
;
;
;
ASCI1_IN:
	CALL	ASCI1_IST
	OR	A
	JR	Z,ASCI1_IN
	IN0	A,(CPU_RDR1)	; READ THE CHAR FROM THE ASCI
	LD	E,A
	RET
;
;
;
ASCI1_IST:
	; CHECK FOR ERROR FLAGS
	IN0	A,(CPU_STAT1)
	AND	70H			; PARITY, FRAMING, OR OVERRUN ERROR
	JR	Z,ASCI1_IST1		; ALL IS WELL, CHECK FOR DATA

	; CLEAR ERROR(S) OR NOTHING FURTHER CAN BE RECEIVED!!!
	IN0	A,(CPU_CNTLA1)
	RES	3,A			; CLEAR EFR (ERROR FLAG RESET)
	OUT0	(CPU_CNTLA1),A

ASCI1_IST1:	; CHECK FOR STAT0.RDRF (DATA READY)
	IN0	A,(CPU_STAT1)		; READ LINE STATUS REGISTER
	AND	$80			; TEST IF DATA IN RECEIVE BUFFER
	JP	Z,CIO_IDLE		; DO IDLE PROCESSING AND RETURN
	XOR	A
	INC	A			; SIGNAL CHAR READY, A = 1
	RET
;
;
;
ASCI1_OUT:
	CALL	ASCI1_OST
	OR	A
	JR	Z,ASCI1_OUT
	LD	A,E
	OUT0	(CPU_TDR1),A
	RET
;
ASCI1_OST:
	IN0	A,(CPU_STAT1)
	AND	$02
	JR	Z,ASCI1_OST
	JP	Z,CIO_IDLE		; DO IDLE PROCESSING AND RETURN
	XOR	A
	INC	A			; SIGNAL BUFFER EMPTY, A = 1
	RET