ME Labs, Inc. | 1-719-520-5323 | Example Program - MWX.pbp

' Name        : MWX.pbp
' Compiler    : PICBASIC PRO Compiler 2.6
' Assembler   : PM or MPASM
' Target PIC  : 40-pin 16F877A, 18F452 or similar
' Hardware    : LAB-X1 Experimenter Board
' Oscillator  : 4MHz external crystal
' Keywords    : SHIFTIN, SHIFTOUT, LCDOUT
' Description : PICBASIC PRO program to read and write to Microwire
' SEEPROM 93LC56A. Writes to the first 16 locations of an external 
' serial EEPROM. Reads first 16 locations back and send to LCD repeatedly.
' Note: for SEEPROMs with byte-sized address.
'

' Define LOADER_USED to allow use of the boot loader.
' This will not affect normal program operation.
Define LOADER_USED 1

' Define LCD registers and bits
Define LCD_DREG  PORTD
Define LCD_DBIT  4
Define LCD_RSREG PORTE
Define LCD_RSBIT 0
Define LCD_EREG  PORTE
Define LCD_EBIT  1

Include "modedefs.bas"

CS  Var PORTA.5  ' Chip select pin
CLK Var PORTC.3  ' Clock pin
DI  Var PORTC.4  ' Data in pin
D0  Var PORTC.5  ' Data out pin

addr Var Byte    ' Address
B0   Var Byte    ' Data

   Low CS        ' Chip select inactive
   ADCON1 = 7    ' Set PORTA and PORTE to digital
   Low PORTE.2   ' LCD R/W line low (W)
   Pause 100     ' Wait for LCD to start up

   Gosub eewriteen     ' Enable SEEPROM writes
   For addr = 0 To 15  ' Loop 16 times
      B0 = addr + 100  ' B0 is data for SEEPROM
      Gosub eewrite    ' Write to SEEPROM
      Pause 10         ' Delay 10ms after each write
   Next addr

mainloop:
   For addr = 0 To 15  ' Loop 16 times
     Gosub eeread      ' Read from SEEPROM
     Lcdout $fe,1,#addr,": ",#B0 ' Display
     Pause 1000
   Next addr

   Goto mainloop       ' Forever

' Subroutine to read data from addr in serial EEPROM
eeread:
   CS = 1              ' Enable serial EEPROM
   Shiftout DI, CLK, MSBFIRST, [%1100\4, addr] ' Send read command and address
   Shiftin D0, CLK, MSBPOST, [B0] ' Read data
   CS = 0              ' Disable
   Return

' Subroutine to write data at addr in serial EEPROM
eewrite:
   CS = 1              ' Enable serial EEPROM
   Shiftout DI, CLK, MSBFIRST, [%1010\4, addr, B0] ' Send write command, address and data
   CS = 0              ' Disable
   Return

' Subroutine to enable writes to serial EEPROM
eewriteen:
   CS = 1              ' Enable serial EEPROM
   Shiftout DI, CLK, MSBFIRST, [%10011\5, 0\7] ' Send write enable command and dummy clocks
   CS = 0              ' Disable
   Return

   End

           

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