AN2183 Freescale Semiconductor / Motorola, AN2183 Datasheet - Page 39

• Manufacturer Part Number: AN2183
• Description: Using FLASH as EEPROM on the MC68HC908GP32
• Manufacturer: Freescale Semiconductor / Motorola

;*
;*
;*
;*
;*
;*
;*
;*
;*
;*
;*
;*
;*
;*
IsHex:
IsHex1:
IsntHex:
;*
;*
;*
;*
;*
;*
;*
;*
;*
;*
;*
;*
;*
;*
PLLset:
AN2183
MOTOROLA
IsHex Subroutine
This subroutine checks if the value passed in ACC is a valid ASCII hex character within
within the ranges of ’0’ to ’9’ or ’A’ to ’F’ or ’a’ to ’f’.
Calling convention:
Returns:
Changes:
CGM PLL Bus Frequency Change Subroutine
This subroutine will program the CGM PLL to change the bus frequency in accordance with
the data being pointed to by H:X.
Calling convention:
Returns:
Changes:
lda
jsr
cmp
blo
cmp
bls
cmp
blo
cmp
bls
sub
cmp
blo
cmp
bhi
bit
rts
ldhx
jsr
bclr
bclr
mov
mov
mov
mov
bset
bset
data
IsHex
CCRZ= 1 if data is a valid hex character.
ACC (if lowercsae)
#’0’
IsntHex
#’9’
IsHex1
#’A’
IsntHex
#’F’
IsHex1
#$20
#’A’
IsntHex
#’F’
IsntHex
#0
#busfreq_table
PLLset
no data
H:X
BCS,pctl
PLLON,pctl
x+,pctl
x+,pmrs
x+,pmsh
x+,pmsl
AUTO,pbwc
PLLON,pctl
=======================================================================
Freescale Semiconductor, Inc.
For More Information On This Product,
Go to: www.freescale.com
; check value against ’0’
; not hex if lower
; check value against ’9’
; is hex if lower
; check value against ’A’
; not hex if lower
; check value against ’F’
; is hex if lower
; adjust to uppercase
; check value against ’A’
; not hex if lower
; check value against ’F’
; isnt hex if higher
; CCRZ= 1
; return
; select external reference as base clock
; turn off PLL
; program P & E
; program L
; program N msb
; program N lsb
; enable automatic bandwidth control
; turn on PLL
================================================
Otherwise, CCRZ= 0.
Adjusts ACC if lowercase.
Application Note
eetest.asm
39