MC68HC705C9A Datasheet, PDF (114/118 Pages) Motorola, Inc – Microcontrollers

EPROM Programming
A.4 Programming Register (PROG)
This register is used to program the EPROM array. To program a byte of EPROM, set LATCH, write data
to the desired address, and set EPGM for t_EPGM.
$001X
Read:
Write:
Reset:
Bit 7
6
5
4
3
2
1
LATCH
0
0
0
0
0
0
0
Figure A-1. EPROM Programming Register
Bit 0
EPGM
0
LATCH — EPROM Latch Control Bit
This read/write bit controls the latching of the address and data buses when programming the EPROM.
1 = Address and data buses latched when the following instruction is a write to 1 of the EPROM
locations. Normal reading is disabled if LATCH = 1.
0 = EPROM address and data bus configured for normal reading
EPGM — EPROM Program Control Bit
This read/write bit controls whether the programming voltage is applied to the EPROM array. For
programming, this bit can be set only if the LATCH bit has been set previously. Both EPGM and LATCH
cannot be set in the single write.
1 = Programming voltage applied to EPROM array
0 = Programming voltage not applied to EPROM array
NOTE
Bits 7–3 and bit 1 MUST be set to 0 when writing to the EPROM
programming register.
MC68HC05C9A Advance Information Data Sheet, Rev. 4.1
114
Freescale Semiconductor