M68HC11
REFERENCE MANUAL
ON-CHIP MEMORY
MOTOROLA
4-11
The following register and paragraphs describe the bits in the PPROG control register.
ODD — Program odd rows in half the EEPROM array
EVEN — Program even rows in half the EEPROM array
These two bits are used only during factory testing of the EEPROM. To program all
bytes in the odd (even) rows on one side of the EEPROM array with the same data in
a single programming operation, set the ODD (EVEN) and EELAT bits to ones, write
to an EEPROM location in an odd (even) row, and then set the EEPGM bit. Since the
onchip V
PP
charge pump does not have enough drive to perform this bulk program-
ming operation, an external 20-V current-limited supply must be connected to the ex-
ternal EEPROM voltage source (IRQ/V
PPBULK
) pin. The intended purpose of this
function is to allow the entire EEPROM array to be filled with a checkerboard pattern
in only four programming operations. This feature is not intended for customer use
since the function serves no practical purpose other than product testing.
BYTE — Byte/Other EEPROM Erase Mode
ROW — Row/All EEPROM Erase Mode
These two bits specify the type of erase operation that is to be performed. These bits
have no meaning when the ERASE bit is clear. The following table shows the relation-
ship between the state of these bits and the type of erase operation that will be per-
formed:
ERASE — Erase/Normal Control of EEPROM
0 = Normal read or program mode
1 = Erase mode
EELAT — EEPROM Latch Control
When this bit is zero, the EEPROM acts as a ROM in the MCU memory map. When
EELAT is one, the EEPROM acts as if it has been removed from the memory map and
placed into a programming socket. Latches on the address and data lines to the
EEPROM array are enabled to capture data and address information needed during
program or erase operations. While EELAT is one, the EEPROM cannot be read,
which implies a software routine that programs or erases EEPROM cannot be execut-
ed from that same EEPROM. The operation of EELAT also implies that programs that
access data from the EEPROM must not be executed while an EEPROM location is
being programmed or erased.
PPROG —
EEPROM Programming Register
$103B
BIT 7
ODD
0
6
5
0
0
4
3
2
1
BIT 0
EEPGM
0
EVEN
0
BYTE
0
ROW
0
ERASE
0
EELAT
0
RESET:
BYTE
0
0
1
1
ROW
0
1
0
1
Type of Erase
Bulk Erase (All 512 Bytes)
Row Erase (16-Byte Row)
Byte Erase
Byte Erase