MIDIfilter/Processor Example 3

Convert CC#0 to NRPN Cutoff for MC303 and CC#1 to NRPN resonance

;
; MIDI Processor
;
; EXAMPLE 3: Convert CC#0 to NRPN Cutoff for MC303 and CC#1 to NRPN resonance
;
; Copyright 2001 by Thorsten Klose
; Commercial use without my permission is strictly forbidden!
;

;; --------------------------------------------------------------------------
;;  PROC Received 8n: called on a Note Off Event
;;  In:	MIDI_LASTEVENT0: 8n, n = midi channel
;;      MIDI_LASTEVENT1: note number
;;      MIDI_LASTEVENT2: velocity
;; --------------------------------------------------------------------------
PROC_Received8n
	movf	MIDI_LASTEVENT0, W
	call	MIDI_SendByte
	movf	MIDI_LASTEVENT1, W
	call	MIDI_SendByte
	movf	MIDI_LASTEVENT2, W
	call	MIDI_SendByte
	return

;; --------------------------------------------------------------------------
;;  PROC Received 9n: called on a Note On Event
;;  In:	MIDI_LASTEVENT0: 9n, n = midi channel
;;      MIDI_LASTEVENT1: note number
;;      MIDI_LASTEVENT2: velocity
;; --------------------------------------------------------------------------
PROC_Received9n
	movf	MIDI_LASTEVENT0, W
	call	MIDI_SendByte
	movf	MIDI_LASTEVENT1, W
	call	MIDI_SendByte
	movf	MIDI_LASTEVENT2, W
	call	MIDI_SendByte
	return

;; --------------------------------------------------------------------------
;;  PROC Received An: called on an Aftertouch Event
;;  In:	MIDI_LASTEVENT0: An, n = midi channel
;;      MIDI_LASTEVENT1: note number
;;      MIDI_LASTEVENT2: preasure
;; --------------------------------------------------------------------------
PROC_ReceivedAn
	movf	MIDI_LASTEVENT0, W
	call	MIDI_SendByte
	movf	MIDI_LASTEVENT1, W
	call	MIDI_SendByte
	movf	MIDI_LASTEVENT2, W
	call	MIDI_SendByte
	return

;; --------------------------------------------------------------------------
;;  PROC Received Bn: called on a Controller Event
;;  In:	MIDI_LASTEVENT0: Bn, n = midi channel
;;      MIDI_LASTEVENT1: CC number
;;      MIDI_LASTEVENT2: CC value
;; --------------------------------------------------------------------------
PROC_ReceivedBn

	;; (note: you could also get the NRPN address with a condition table,
	;;  which would save a lot of code - this example is just for
	;;  education)

	;; branch when CC number is 0x00
	movf	MIDI_LASTEVENT1, W
	xorlw	0x00
	bz	PROC_ReceivedBn00
	
	;; branch when CC number is 0x01
	movf	MIDI_LASTEVENT1, W
	xorlw	0x01
	bz	PROC_ReceivedBn01

	movf	MIDI_LASTEVENT0, W
	call	MIDI_SendByte
	movf	MIDI_LASTEVENT1, W
	call	MIDI_SendByte
	movf	MIDI_LASTEVENT2, W
	call	MIDI_SendByte
	return


	;; the other variants
PROC_ReceivedBn00
	movlw	0x20				; NRPN LSB = 0x20
	goto	PROC_ReceivedBn_SendNRPN	; continue here
	
PROC_ReceivedBn01
	movlw	0x21				; NRPN LSB = 0x20

	;; goto	PROC_ReceivedBn_SendNRPN	; continue here
	;; (this jump is not really necessary, since the target is the next instr.)

PROC_ReceivedBn_SendNRPN
	movwf	TMP1				; store number in temp. register

	movf	MIDI_LASTEVENT0, W		; send Bn
	call	MIDI_SendByte
	movlw	0x63				; Send NRPN MSB 01 (0x63 0x01)
	call	MIDI_SendByte
	movlw	0x01
	call	MIDI_SendByte
	movlw	0x62				; SEND NRPN LSB  (0x62 )
	call	MIDI_SendByte
	movf	TMP1, W
	call	MIDI_SendByte
	movlw	0x06				; send NRPN MSB value (06 )
	call	MIDI_SendByte
	movf	MIDI_LASTEVENT2, W
	call	MIDI_SendByte
	return

	
;; --------------------------------------------------------------------------
;;  PROC Received Cn: called on a Controller Event
;;  In:	MIDI_LASTEVENT0: Cn, n = midi channel
;;      MIDI_LASTEVENT2: program number (AND NOT MIDI_LASTEVENT1!)
;; --------------------------------------------------------------------------
PROC_ReceivedCn
	movf	MIDI_LASTEVENT0, W
	call	MIDI_SendByte
	movf	MIDI_LASTEVENT2, W
	call	MIDI_SendByte
	return

;; --------------------------------------------------------------------------
;;  PROC Received Dn: called on a Poly Aftertouch Event
;;  In:	MIDI_LASTEVENT0: Dn, n = midi channel
;;      MIDI_LASTEVENT2: note number (AND NOT MIDI_LASTEVENT1!)
;; --------------------------------------------------------------------------
PROC_ReceivedDn
	movf	MIDI_LASTEVENT0, W
	call	MIDI_SendByte
	movf	MIDI_LASTEVENT2, W
	call	MIDI_SendByte
	return

;; --------------------------------------------------------------------------
;;  PROC Received En: called on an Pitch Bender Event
;;  In:	MIDI_LASTEVENT0: En, n = midi channel
;;      MIDI_LASTEVENT1: Pitch Bender High Byte
;;      MIDI_LASTEVENT2: Pitch Bender Low Byte
;; --------------------------------------------------------------------------
PROC_ReceivedEn
	movf	MIDI_LASTEVENT0, W
	call	MIDI_SendByte
	movf	MIDI_LASTEVENT1, W
	call	MIDI_SendByte
	movf	MIDI_LASTEVENT2, W
	call	MIDI_SendByte
	return

;; --------------------------------------------------------------------------
;;  PROC Received Fx: called on an System Event
;;  In: MIDI_LASTEVENT0: Fx, x = System Service
;;      MIDI_LASTEVENT1: contains the byte of a sysex or MTC stream when
;;                       MIDI_FxSTATUS != 0
;;      MIDI_FxSTATUS:   if 0, send MIDI_LASTEVENT0, else MIDI_LASTEVENT1
;; --------------------------------------------------------------------------
PROC_ReceivedFx
        ;; branch depending on MIDI_FxSTATUS
        movf    MIDI_FxSTATUS, W
        bnz     PROC_ReceivedFx_SendByte
        
PROC_ReceivedFx_SendCommand
        movf    MIDI_LASTEVENT0, W
        call    MIDI_SendByte
        return

PROC_ReceivedFx_SendByte
        movf    MIDI_LASTEVENT1, W
        call    MIDI_SendByte
        return
Last update: 2023-11-04