ST ST7 - Page 177

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6 - STMicroelectronics Programming Tools
;* declarations are in the include file REG72251.INC that
;* must be included in the source files that use them.
;*************************************************************
BYTES ; the following addresses are 8-bit long
;*************************************************************
segment byte at 0-71 'periph'
;*************************************************************
;*************************************************************
; I/O Ports registers
;*************************************************************
.pcdr DS.B 1 ; port C data register
.pcddr DS.B 1 ; port C data direction register
.pcor DS.B 1 ; port C option register
DS.B 1 ; empty byte
.pbdr DS.B 1 ; port B data register
.pbddr DS.B 1 ; port B data direction register
.pbor DS.B 1 ; port B option register
DS.B 1 ; empty byte
(tobecontinued)
When you get to the point of inserting
EXTERN declarations in the source files, you have two
choices:
You may add only the external declarations you need;
You may include the
REGISTER.INC file, and get the whole set of externaldeclarations at once,
since adding useless externals does no harm. This method is obviously quicker and easier.
Here is an excerpt from the
REGISTER.INC file:
;
;*************************************************************
;* ST72251 registers
;* This file contains the EXTERN declarations for all
;* the peripheral registers and the EQUates for the bit
;* positions within the registers. It must be included
;* in source files that use the peripherals.
;*************************************************************
BYTES ; the following addresses are 8-bit long
;*************************************************************
; I/O Ports registers
;*************************************************************