memeory settings FX2

I have code for spibytewrite only .Iam using PORT E.PE.0 is my SCLK and PE.7 is my SDO and PE.3 is my CS.

?PR?SPIWRITEBYTE?MODULE segment code
 ?DT?SPIWRITEBYTE?MODULE segment data overlayable

 PUBLIC _spiwritebyte, ?_spiwritebyte?BYTE

 rseg ?DT?SPIWRITEBYTE?MODULE
 ?_spiwritebyte?BYTE:
 d: ds 1

 rseg ?PR?SPIWRITEBYTE?MODULE

 CLKHIGH equ 00000001B ;Bitmask to turn clk pin high
 CLKLOW equ  11111110B ;Bitmask to turn clk pin low
 BITHIGH equ 10000000B ;Bitmask to turn out pin high
 BITLOW equ  01111111B ;Bitmask to turn out pin low

 IOE XDATA 0xB1 ;7F98H

 _spiwritebyte:

 mov DPTR,#IOE ;point to IOE
 mov R6, #8 ;set up loop
 loop:
 mov A, R7 ;move data to send to A
 rrc A ;rotate left through carry to send LSB first
 mov R7, A ;save rotated
 movx A, @DPTR ;setup to change bit
 jc highbit ;if bit is high jump
 anl A, #BITLOW ;else set bit low
 sjmp skip ;skip setting bit high
 highbit:
 orl A, #BITHIGH ;set out high and clock
 skip:
 orl A, #CLKHIGH ;set clock bit high
 movx @DPTR, A ;output data
 nop ;may need this to stretch clock high time
 anl A, #CLKLOW ;set clock low
 movx @DPTR, A ;output low clock
 djnz R6, loop ;repeat eight times
 ret
 end

Vanitha

I have code for spibytewrite only .Iam using PORT E.PE.0 is my SCLK and PE.7 is my SDO and PE.3 is my CS.

?PR?SPIWRITEBYTE?MODULE segment code
 ?DT?SPIWRITEBYTE?MODULE segment data overlayable

 PUBLIC _spiwritebyte, ?_spiwritebyte?BYTE

 rseg ?DT?SPIWRITEBYTE?MODULE
 ?_spiwritebyte?BYTE:
 d: ds 1

 rseg ?PR?SPIWRITEBYTE?MODULE

 CLKHIGH equ 00000001B ;Bitmask to turn clk pin high
 CLKLOW equ  11111110B ;Bitmask to turn clk pin low
 BITHIGH equ 10000000B ;Bitmask to turn out pin high
 BITLOW equ  01111111B ;Bitmask to turn out pin low

 IOE XDATA 0xB1 ;7F98H

 _spiwritebyte:

 mov DPTR,#IOE ;point to IOE
 mov R6, #8 ;set up loop
 loop:
 mov A, R7 ;move data to send to A
 rrc A ;rotate left through carry to send LSB first
 mov R7, A ;save rotated
 movx A, @DPTR ;setup to change bit
 jc highbit ;if bit is high jump
 anl A, #BITLOW ;else set bit low
 sjmp skip ;skip setting bit high
 highbit:
 orl A, #BITHIGH ;set out high and clock
 skip:
 orl A, #CLKHIGH ;set clock bit high
 movx @DPTR, A ;output data
 nop ;may need this to stretch clock high time
 anl A, #CLKLOW ;set clock low
 movx @DPTR, A ;output low clock
 djnz R6, loop ;repeat eight times
 ret
 end

Vanitha

I solved the problem finally. The IOE in FX2 is located in direct memory access region. The indirect addressing (movx @DPTR, A ) was causing problem. Simply it can be written as mov 0xB1,A. DPTR is not required as it is used to access external memory.
Vanitha