HC805K3GRSSLASHD datasheet(86/119 Pages) NXP

86 / 119 page

General Release Speciﬁcation

PEEPROM Programming

MC68HC805K3 — Rev. 1.0

Personality EEPROM

9.4 PEEPROM Programming

The PEEPROM can be programmed using a Motorola programmer or in

the user application if the VDD supply source is at least 3.0 Vdc. In the

latter case, the programming software must be provided in the user

EEPROM and use some external pins in either a serial or parallel

method for data transfer and/or access. Each bit of the PEEPROM can

be programmed as follows:

1. Write the desired bit location to be programmed into the PEBSR

located at $000E.

2. Set the PEPGM and CPEN bits in the PESCR located at $000F.

3. Wait for a tEPGM time delay.

4. Clear the PEPGM and CPEN bits.

The PEEPROM is then ready to be set up for another bit of data for

programming.

The programming of a PEEPROM bit only requires access of that bit

through the PEBSR followed by setting the PEPGM and CPEN bits in

the PESCR. Do not access any bits that are to be left unprogrammed

(erased) until all the PEPGM, PEBYTE, PEBULK, and CPEN bits in the

PESCR are cleared. Always clear the PEPGM, PEBYTE, PEBULK, and

CPEN bits before altering the PEBSR register.

9.5 PEEPROM Read Access

The contents of the PEEPROM are read by the following sequence:

1. Write the desired bit location to be read into the PEBSR located at

$000E.

2. Read the state of the PEDATA bit in the PESCR located at $000F.

3. Store the state of the PEDATA bit into RAM or a register.

4. Select another bit by changing the PEBSR.

5. Continue reading and storing the PEDATA bit states until all the

required PEEPROM data has been accessed.

Freescale Semiconductor, Inc.

For More Information On This Product,

Go to: www.freescale.com

HC805K3GRS/D Datasheet(PDF) 86 Page - NXP Semiconductors