|
MC68HC05L28 Datasheet, PDF (139/156 Pages) Motorola, Inc – Flexible general-purpose microcomputer | |||
|
◁ |
A.4
EPROM programming register (PCR)
EPROM program (PCR)
Address bit 7
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
State
on reset
$001C
ELAT PGM uuuu uu0u
A.4.1 ELAT â EPROM latch control
1 (set)
â When this bit is set to 1, the EPROM address and data buses are
conï¬gured for programming. This causes the address and data
buses to be latched when a write to EPROM is executed. The
EPROM cannot be read if it is set to 1.
0 (clear) â The EPROM address and data buses are conï¬gured for normal
reads.
A.4.2 PGM â EPROM program control
1 (set)
â Programming power is connected to the EPROM array.The PGM can
only be set if ELAT is set and it is automatically cleared when ELAT =
0.
0 (clear) â EPROM address and data bus are conï¬gured for normal reads.
Note: ELAT and PGM cannot be set in the same write operation.
Take the following steps to program a byte of EPROM:
â Apply the programming voltage VPP to the VPP pin.
â Set the ELAT bit.
â Write to the EPROM address.
â Set the PGM bit for a time tPROG to apply the programming voltage.
â Clear the ELAT and PGM bits.
Note: The erased state of the EPROM is $00.
MC68HC05L28
MC68HC705L28
TPG
MOTOROLA
A-5
15
|
▷ |