list	p=18f242
        include <p18f242.inc>
        include <coff.inc>


	;; The purpose of this program is to test gpsim's ability to simulate a pic 16F88.
	;; Specifically, SPI

        errorlevel -302 

; Printf Command
.command macro x
  .direct "C", x
  endm


#define SDO_PORT PORTC,5
#define SDI_PORT PORTC,4
#define SCK_PORT PORTC,3
#define SS_PORT PORTA,5

#define SDO_TRIS TRISC,5
#define SDI_TRIS TRISC,4
#define SCK_TRIS TRISC,3
#define SS_TRIS TRISA,5

#define DRV_CLOCK PORTA,1
#define DRV_CLOCK_TRIS TRISA,1


;----------------------------------------------------------------------
;----------------------------------------------------------------------
GPR_DATA                UDATA

w_temp RES  1
status_temp RES  1
loopcnt	RES	1



;----------------------------------------------------------------------
;   ********************* RESET VECTOR LOCATION  ********************
;----------------------------------------------------------------------
RESET_VECTOR  CODE    0x000              ; processor reset vector
        movlw  high  start               ; load upper byte of 'start' label
        movwf  PCLATH                    ; initialize PCLATH
        goto   start                     ; go to beginning of program

	;; 
	;; Interrupt
	;; 
	movwf	w_temp
	swapf	STATUS,W
	movwf	status_temp

        btfss   INTCON,SSPIF
        goto    check	                ; other Interrupts
;        bsf     _TIME_OUT_              ; MUST set this Flag
        bcf     INTCON,SSPIF


check:
	swapf	status_temp,w
	movwf	STATUS
	swapf	w_temp,F
	swapf	w_temp,W
	retfie



;----------------------------------------------------------------------
;   ******************* MAIN CODE START LOCATION  ******************
;----------------------------------------------------------------------
MAIN    CODE
start:

   .sim "module lib libgpsim_modules"
   .sim "module load pu pu1"
   .sim "module load pu pu2"
   .sim "module load not not"
;   .sim "p16f88.xpos = 132."
;   .sim "p16f88.ypos = 96."

   .sim "not.xpos=252."
   .sim "not.ypos=216."

   .sim "pu1.xpos=84."
   .sim "pu1.ypos=316."

   .sim "pu2.xpos=228."
   .sim "pu2.ypos=108."

   .sim "node ss"
   .sim "attach ss porta5 porta2"	; Not SS
   .sim "node sck"
   .sim "attach sck portc3 porta1 pu1.pin"	; SCK
   .sim "node sdo"
   .sim "attach sdo not.in0 portc5 pu2.pin"
   .sim "node sdi"
   .sim "attach sdi portc4 not.out"

    movlw	0xf6	; set internal RC to 8 Mhz
    movwf	OSCCON
    bcf		SDO_TRIS	; SDO
    bcf		SCK_TRIS	; SCK
    movlw	0xff
    movwf	SSPSTAT
  .assert "sspstat == 0xC0, \"SPI sspstat only SMP, CKE writable\""
    clrf	SSPSTAT


;
;  	Test SPI Master mode
;
    movlw	0x21	; SSPEN | SPI master Fosc/16
    movwf	SSPCON1
    bcf		PIR1,SSPIF
    movlw	0xab
    movwf	SSPBUF

loop:
    btfss	PIR1,SSPIF
    goto	loop

  .assert "(sspstat & 1) == 1, \"FAILED MSSP SPI Master BF not set\""
    nop
    movf	SSPBUF,W
  .assert "(sspstat & 1) == 0, \"FAILED MSSP SPI Master BF not cleared\""
    nop
  .assert "W == 0x54, \"FAILED MSSP SPI Master wrong data\""
    nop

;
;	TEST SPI Slave mode with SS
;
    clrf	SSPCON1
    bcf		DRV_CLOCK_TRIS 	; external SCK drive
    bsf		SCK_TRIS	; SCK
    bsf		SS_TRIS 	; SS
    bcf		DRV_CLOCK
    movlw	0x24	; SSPEN | SPI slave mode SS enable
    movwf	SSPCON1
    bcf		PIR1,SSPIF
    movlw	0xab
    movwf	SSPBUF
    bsf		DRV_CLOCK
    bcf		DRV_CLOCK
    movwf	SSPBUF	; test WCOL set
  .assert "(sspcon & 0x80) == 0x80, \"FAILED MSSP SPI WCOL set\""
    nop
    bcf		SSPCON1,WCOL	; clear WCOL bit
  .assert "(sspcon & 0x80) == 0x00, \"FAILED MSSP SPI WCOL was cleared\""
    nop
    clrf	loopcnt
loop2:
    incf	loopcnt,F
    bsf		DRV_CLOCK
    bcf		DRV_CLOCK
    btfss	PIR1,SSPIF
    goto	loop2

    movf	SSPBUF,W
  .assert "W == 0x54, \"FAILED MSSP SPI Slave data\""
    nop
;
;	Test Slave receive overrun
;
   movlw	0x10
   movwf	loopcnt
loop4:
    bsf		DRV_CLOCK
    bcf		DRV_CLOCK
    decfsz	loopcnt,F
    goto	loop4
  .assert "(sspcon & 0x40) == 0x40, \"FAILED MSSP SPI SSPOV\""
    nop

;
;  	Test SPI Master mode TMR2
;
    clrf	SSPCON1
    bsf		DRV_CLOCK_TRIS	; external SCK drive off
    bcf		SCK_TRIS	; SCK output
    movlw	0x1
    movwf	PR2
    clrf	TMR2
    movlw	0x3C	; prescale = 1 postscale 16
    movwf	T2CON

    movlw	0x23	; SSPEN | SPI master TMR2
    movwf	SSPCON1
    bcf		PIR1,SSPIF
    movlw	0xab
    movwf	SSPBUF

loop3:
    btfss	PIR1,SSPIF
    goto	loop3

  .assert "(sspstat & 1) == 1, \"FAILED MSSP SPI Master TMR2, BF not set\""
    nop
    movf	SSPBUF,W
  .assert "(sspstat & 1) == 0, \"FAILED MSSP SPI Master TMR2, BF not cleared\""
    nop
  .assert "W == 0x54, \"FAILED MSSP SPI Master TMR2 wrong data\""
    nop

  .assert "\"*** PASSED 18f424 MSSP SPI test\""
    
    goto $

	end