MC68HC705P9CS datasheet(37/160 Pages) FREESCALE

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Memory

EPROM/OTPROM

MC68HC705P9 — Rev. 4.0

Technical Data

MOTOROLA

Memory

3.6 EPROM/OTPROM

An MCU with a quartz window has 2104 bytes of erasable,

programmable ROM (EPROM). The quartz window allows EPROM

erasure with ultraviolet light.

NOTE:

Keep the quartz window covered with an opaque material except when

programming the MCU. Ambient light may affect MCU operation.

In an MCU without the quartz window, the EPROM cannot be erased

and serves as 2104 bytes of one-time programmable ROM (OTPROM).

The following addresses are user EPROM/OTPROM locations:

•

$0020–$004F

•

$0100–$08FF

•

$1FF8–$1FFF (reserved for user-defined interrupt and reset

vectors)

The mask option register (MOR) is an EPROM/OTPROM location at

address $0900.

3.6.1 EPROM/OTPROM Programming

The two ways to program the EPROM/OTPROM are:

•

Manipulating the control bits in the EPROM programming register

to program the EPROM/OTPROM on a byte-by-byte basis

•

Activating the bootloader ROM to download the contents of an

external memory device to the on-chip EPROM/OTPROM

Freescale Semiconductor, Inc.

For More Information On This Product,

Go to: www.freescale.com

MC68HC705P9CS Datasheet(PDF) 37 Page - Freescale Semiconductor, Inc