MC68HC705T16 MOTOROLA [Motorola, Inc], MC68HC705T16 Datasheet - Page 115

• Manufacturer Part Number: MC68HC705T16
• Description: High-density complementary metal oxide semiconductor (HCMOS) microcontroller unit
• Manufacturer: MOTOROLA [Motorola, Inc]

ELAT - EPROM Latch Control
PGM - EPROM Program Command
13.3.3
Programming the EPROM of the MC68HC705T16 is as follows:
The last action may be carried out in a single CPU write operation. It is important to remember
that an external programming voltage must be applied to the V
should be equal to V
Example shows address $B000 is programmed with $00.
CLR
LDX
BSET
LDA
STA
BSET
JSR
CLR
MC68HC05T16
1 (set)
0 (clear) –
1 (set)
0 (clear) –
1) Set the ELAT bit.
2) Write the data to be programmed to the address to be programmed.
3) Set the PGM bit.
4) Delay for the appropriate amount of time.
5) Clear the PGM and the ELAT bits.
PCR
#$00
1,PCR
#$00
$B000,X
0,PCR
DELAY
PCR
EPROM Programming Sequence
–
–
DD
EPROM address and data bus configured for programming (writes to
EPROM cause address data to be latched). EPROM is in
programming mode and cannot be read if ELAT is 1. This bit should
not be set unless a programming voltage is applied to the V
EPROM address and data bus configured for normal reads.
Programming power connected to the EPROM array. If ELAT not = 1
then PGM = 0.
Programming power disconnected from the EPROM array.
during normal operation.
;EPROM, the address should be in the range of
;$8000 to $8FFF)
;reset PCR
;load index register with 00
;set ELAT bit
;load data=00 in to A
;latch data and address (if programming OSD CHAR
;program
;call delay subroutine for 1ms
;reset PCR
OPERATING MODES
PP
pin while programming, but
PP
pin.
MOTOROLA
TPG
13-5
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