In SX Microcontrollers, SX/B Compiler and SX-Key Tool, Zamuel_a wrote:

Here is the code but it might be alittle confusing.
There are alot's of "dummy" nops in some routines that I put in to prevent the "read modify write" problem, but it didn't make any difference
The loop works ok upto about 230, above that and it's very unstable and if I run it for about 250 loops it never works. The loop should go on for 65536 loops and it worked then I forced the resetpin high


;-------------------------- DEVICE DIRECTIVES --------------------------

		DEVICE		SX28,OSCHS3,TURBO

IFDEF	__SASM  ;SASM Directives
		DEVICE		STACKX,OPTIONX
		IRC_CAL		IRC_SLOW
		
ELSE		;Parallax Assembler Directives
		DEVICE		STACKX_OPTIONX
ENDIF

		RESET		initialize

;---------------------------- DEBUG SETTINGS ---------------------------

		FREQ	4_000_000

;------------------------------ VARIABLES ------------------------------

data_low	EQU	$08
data_high	EQU	$09
temp		EQU	$0E

		ORG	$000

;------------------------ INITIALIZATION ROUTINE -----------------------

WE	EQU	RA.3
OE	EQU	RA.2
BUSY	EQU	RA.1
ADDR_EN	EQU	RA.0

A0A7	EQU	RB
A8A15	EQU	RC
D0D7	EQU	RB
D8D15	EQU	RC


;Port signals
SX_LOAD_ADDR_EN	MACRO
		setb	ADDR_EN
		ENDM

SX_LOAD_ADDR_DI	MACRO
		clrb	ADDR_EN
		ENDM

SX_OE_HIGH	MACRO
		setb	OE
		ENDM

SX_OE_LOW	MACRO
		clrb	OE
		ENDM

SX_WE_HIGH	MACRO
		setb	WE
		ENDM

SX_WE_LOW	MACRO
		clrb	WE
		ENDM

;Set RAM address A0-A15
SETADDR		MACRO	ADDRH ADDRL
		nop
		nop
		mov	!A0A7,#$00 	;Port B all outputs, LOW
		nop
		nop
		mov	!A8A15,#$00 	;Port C all outputs, HIGH
		nop
		nop
		mov	A0A7,ADDRL
		nop
		nop
		mov	A8A15,ADDRH
		nop
		nop
		SX_LOAD_ADDR_EN
		nop
		nop
		nop
		nop
		nop
		SX_LOAD_ADDR_DI
		nop
		nop
		ENDM

;Read data from D0-D15 to DESTH and DESTL
READ_DATA	MACRO	DESTH,DESTL
		mov	!A0A7,#$FF 	;Port B all inputs, LOW
		mov	!A8A15,#$FF 	;Port C all inputs, HIGH
		nop
		nop
		nop
		SX_OE_LOW		;Read data
		nop			;1 nop räcker?
		nop
		nop
		nop
		mov	DESTL,D0D7
		mov	DESTH,D8D15
		SX_OE_HIGH
		ENDM


;Add a 16 bit value with a 8 bit value
ADD16_8		MACRO	ARG1,ARG2
		add	ARG1,ARG2
		snc
		inc	ARG1 + 1
		ENDM

;------------------------ INITIALIZATION ROUTINE -----------------------

initialize

	mode	$0F 			;Set Mode to allow Direction configuration

;---------------------------- MAIN PROGRAM -----------------------------
main

	clrb	RA.1		;Enable BUSY signal
	mov	!RA,#%0000 	;Port A all outputs
	mov	RA,#%1100	;No WE or OE to RAM yet

	mov	temp,#0
	mov	temp+1,#0

loop
	SETADDR	temp+1,temp
	READ_DATA	data_high,data_low

	ADD16_8	temp,#1
	cjbe	temp+1,#$FF,loop
;	cjbe	temp,#230,loop

loop2	jmp	loop2


	END

---------- End of Message ----------


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