mc68hc05jb4p Freescale Semiconductor, Inc, mc68hc05jb4p Datasheet - Page 129

• Manufacturer Part Number: mc68hc05jb4p
• Description: Mc68hc705jb4 Microcontroller
• Manufacturer: Freescale Semiconductor, Inc

A.5
A.5.1 EPROM Program Control Register (PCR)
A.5.2 Programming Sequence
MC68HC05JB4
REV 2
The user code must be a one-to-one correspondence with the internal EPROM
addresses.
EPROM PROGRAMMING
Programming the on-chip EPROM is achieved by using the Program Control Reg-
ister located at address $3E.
Please contact Freescale for programming board availability.
This register is provided for programming the on-chip EPROM in the
MC68HC705JB4.
MORON – Mask Option Register ON
ELAT – EPROM LATch control
PGM – EPROM ProGraM command
The EPROM programming sequence is:
The last two steps must be performed with separate CPU writes.
PCR
$003E
1. Set the ELAT bit
2. Write the data to the address to be programmed
3. Set the PGM bit
4. Delay for a time t
5. Clear the PGM bit
6. Clear the ELAT bit
reset:
0 = Disable programming to Mask Option Register ($007F)
1 = Enable programming to Mask Option Register ($007F)
0 = EPROM address and data bus configured for normal reads
1 = EPROM address and data bus configured for programming (writes
0 = Programming power is switched OFF from EPROM array.
1 = Programming power is switched ON to EPROM array. If ELAT
W
R
to EPROM cause address and data to be latched). EPROM is in
programming mode and cannot be read if ELAT is 1. This bit should
not be set when no programming voltage is applied to the V
then PGM = 0.
BIT 7
0
Freescale Semiconductor, Inc.
For More Information On This Product,
BIT 6
0
PGMR
Go to: www.freescale.com
RESERVED
February 24, 1999
BIT 5
0
BIT 4
0
GENERAL RELEASE SPECIFICATION
BIT 3
0
MORON
BIT 2
0
ELAT
BIT 1
0
pp
pin.
BIT 0
PGM
0
1,