In SX Microcontrollers, SX/B Compiler and SX-Key Tool, tdg8934 wrote:

I tried inserting a PAUSE 50 between each LOW and HIGH control signal and still no output on the LEDs. 
I need some help perhaps by Parallax or Bean maybe to see what is so different in the timing between the SX-28 and the BS2. I have tried everything under the sun and the SX-28 program still shows no output LED's unlike the BS2 version which is running fine with no extra PAUSE statements needed. 

Perhaps since it is the work week now, I can get some more help with a different perspective.

[code]
' =========================================================================
'
'   File...... 8255_Test.SXB
'   Purpose... SX/B interface to 8255
'   Author.... Timothy Gilmore
'   E-mail.... [url=gilmoret@us.saic.com]gilmoret@us.saic.com[/url]
'   Started... 21 OCT 2006
'   Updated... 22 OCT 2006
'
' ========================================================================= 


' -------------------------------------------------------------------------
' Program Description
' -------------------------------------------------------------------------
' BS2 conversion program to SX-28 interface with an 8255 

' -------------------------------------------------------------------------
' Device Settings
' ------------------------------------------------------------------------- 

DEVICE          SX28, OSC4MHZ, TURBO, STACKX, OPTIONX    'Use no external resonator
FREQ            4_000_000
ID              "SXB 1.50" 


' -------------------------------------------------------------------------
' IO Pins
' -------------------------------------------------------------------------
Reset_8255 PIN RB.0 OUTPUT
WR_8255  PIN RB.1 OUTPUT
A0_8255  PIN RB.2 OUTPUT
A1_8255  PIN RB.3 OUTPUT 

CS1_8255 PIN RB.4 OUTPUT 

RB_OUT  PIN RB OUTPUT
RC_OUT  PIN RC OUTPUT 


' -------------------------------------------------------------------------
' Constants
' ------------------------------------------------------------------------- 


' -------------------------------------------------------------------------
' Variables
' -------------------------------------------------------------------------
pattern1 VAR Byte
pattern2 VAR Byte
pattern3 VAR Byte                        


' =========================================================================
  PROGRAM Start
' ========================================================================= 


' -------------------------------------------------------------------------
' Subroutine Declarations
' -------------------------------------------------------------------------
Initialize_8255 SUB
PortA_8255 SUB
PortB_8255 SUB
PortC_8255 SUB 

' -------------------------------------------------------------------------
' Program Code
' ------------------------------------------------------------------------- 

Start:
  ' initialization code here
 
RB_OUT = $00  'RB pins are set LOW (Control lines Active Low)
RC_OUT = $00  'RC pins are set LOW 

Initialize_8255 


Main:
  ' main code here 

pattern1 = %10101010 'Set patterns for the 8255 Output Ports (Read it in reverse)
pattern2 = %11110000
pattern3 = %00110011 

PortA_8255  'GOSUB to the Portx_8255 routines
'PortB_8255
'PortC_8255 

GOTO Main 


' -------------------------------------------------------------------------
' Subroutine Code
' -------------------------------------------------------------------------
Initialize_8255: 'Initialize 8255 to All Outputs at Active Low state
 RB_OUT = $FF  'RB pins (Control lines are set Inactive HIGH) 
 PAUSE 50  'Settling time for a few ms (50 ms)
 LOW Reset_8255  '8255 is Reset (Active)
 PAUSE 50
 HIGH WR_8255  'Set Write control High (Inactive)
 PAUSE 50
 HIGH A1_8255  'Set Address control A1 & A0 High to access the control word register
 PAUSE 50
 HIGH A0_8255
 PAUSE 50
 RC_OUT = $80  'Set databus (D0-D1 of 8255) to $80 for MODE 0 - All 3 8255 ports as outputs
 LOW CS1_8255  'Set Chip Select Low (Active)
 PAUSE 50
 PULSOUT WR_8255, 10 'Pulse Write control Low (Active) for 100 us (duration not critical)
 PAUSE 50
 HIGH CS1_8255  'Set Chip Select High (Inactive) - All 8255 outputs are set to Active Low
 PAUSE 50  'HOLD TIME FOR 50 MS
 RETURN 

PortA_8255:  'Set up 8255 Port A for Output
 LOW A1_8255  'Set Address control A1 & A0 Low to set the 8255 Port A for Output
 PAUSE 50
 LOW A0_8255
 PAUSE 50
 RC_OUT = pattern1 'Set databus for pattern1
 LOW CS1_8255  'Set Chip Select Low (Active)
 PULSOUT WR_8255, 1 'Pulse Write control Low (Active) for 10 us (port changes state)
 PAUSE 50
 HIGH CS1_8255  'Set Chip Select High (Inactive) - Disable the 8255 databus
 PAUSE 50  'HOLD TIME FOR 50 MS
 RETURN 

  

  

PortB_8255:  'Set up 8255 Port B for Output
 HIGH A1_8255  'Set Address control A1 & A0 to set the 8255 Port B for Output
 LOW A0_8255
 RC_OUT = pattern2 'Set databus for pattern2
 LOW CS1_8255  'Set Chip Select Low (Active)
 PULSOUT WR_8255, 1 'Pulse Write control Low (Active) for 10 us (port changes state)
 HIGH CS1_8255  'Set Chip Select High (Inactive) - Disable the 8255 databus
 PAUSE 50  'HOLD TIME FOR 50 MS
 RETURN 

PortC_8255:  'Set up 8255 Port C for Output
 LOW A1_8255  'Set address control A1 & A0 to set the 8255 Port C for Output
 HIGH A0_8255
 RC_OUT = pattern3  'Set databus for pattern3
 LOW CS1_8255  'Set Chip Select Low (Active)
 PULSOUT WR_8255, 1 'Pulse Write control Low (Active) for 10 us (port changes state)
 HIGH CS1_8255  'Set Chip Select High (Inactive) - Disable the 8255 databus
 PAUSE 50  'HOLD TIME FOR 50 MS
 RETURN 

' =========================================================================
' User Data
' ========================================================================= 

'Pgm_ID:
'  DATA  "SX/B 1.50 Template", 0
 

THIS SX-28 PROGRAM (ABOVE) DOES NOT WORK
 
THIS BS2 PROGRAM (BELOW) DOES WORK ---- WHAT IS DIFFERENT BETWEEN THEM?
[/code]

[code]
' {$STAMP BS2px}
' {$PBASIC 2.5}
'
' 8255 PPI IC - Test program with 24 outputs available.
' Written by Timothy Gilmore
' 10/15/06
'
' Test program using the 8255 and BS2PX (OR BS2).
'
' ----- Constants 

Reset_8255    PIN     8
WR_8255       PIN     9
A0_8255       PIN     10
A1_8255       PIN     11
CS_8255       PIN     12
' 3 additional 8255 chips can be used when using:
' CS2_8255   PIN 13
' CS3_8255   PIN 14
' CS4_8255   PIN 15
' This would provide 24+24+24 additional inputs and/or outputs (96 I/O lines possible)
' Modify the code below to add the 3 additional Chip Select lines if needed to add more 8255's. 

' ----- Variables
pattern1       VAR     Byte
pattern2       VAR     Byte
pattern3       VAR     Byte 

' ----- EEPROM Data 


' ----- Initialization 

OUTS = $00              ' Set Outputs Low
DIRS = $FF              ' Set I/O Direction 

GOSUB Initialize_8255 


' ----- Main Code
Main: 

pattern1 = %10101010     'Set pattern for Output Ports (Read it in reverse)
pattern2 = %11110000
pattern3 = %00110011 


GOSUB PortA_8255 

GOSUB PortB_8255 

GOSUB PortC_8255 

  

 GOTO Main 

' ----- Subroutines
Initialize_8255:          'Initialize 8255 to All Outputs at Active Low state
 OUTH = $FF               'Set all the control lines (P8-P15) High (Inactive)
 PAUSE 50                 'Settling time for a few ms (50 ms)
 LOW Reset_8255           '8255 is Reset (Active)
 HIGH WR_8255             'Set Write control High (Inactive)
 HIGH A1_8255             'Set Address control A1 & A0 High to access the control word register
 HIGH A0_8255
 OUTL = $80               'Set databus (P0-P7) to $80 for MODE 0 - All 3 ports as outputs
 LOW CS_8255              'Set Chip Select Low (Active)
 PULSOUT WR_8255, 50      'Pulse Write control Low (Active) for 100 us (duration not critical)
 HIGH CS_8255             'Set Chip Select High (Inactive) - All outputs are set to Active Low
 RETURN 


PortA_8255:               'Set up 8255 Port A for Output
 LOW A1_8255              'Set address control A1 & A0 Low to set the 8255 Port A for Output
 LOW A0_8255
 OUTL = pattern1          'Set databus for pattern1
 LOW CS_8255              'Set Chip Select Low (Active)
 PULSOUT WR_8255, 5       'Pulse Write control Low (Active) for 10 us (port changes state)
 HIGH CS_8255             'Set Chip Select High (Inactive) - Disable the 8255 databus
 RETURN 

PortB_8255:               'Set up 8255 Port B for Output
 HIGH A1_8255             'Set address control A1 & A0 to set the 8255 Port B for Output
 LOW A0_8255
 OUTL = pattern2          'Set databus for pattern2
 LOW CS_8255              'Set Chip Select Low (Active)
 PULSOUT WR_8255, 5       'Pulse Write control Low (Active) for 10 us (port changes state)
 HIGH CS_8255             'Set Chip Select High (Inactive) - Disable the 8255 databus
 RETURN 

PortC_8255:               'Set up 8255 Port C for Output
 LOW A1_8255              'Set address control A1 & A0 to set the 8255 Port C for Output
 HIGH A0_8255
 OUTL = pattern3          'Set databus for pattern3
 LOW CS_8255              'Set Chip Select Low (Active)
 PULSOUT WR_8255, 5       'Pulse Write control Low (Active) for 10 us (port changes state)
 HIGH CS_8255             'Set Chip Select High (Inactive) - Disable the 8255 databus
 RETURN
 
[/code]

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