MC908MR16CFUE Datasheet, PDF(39/282 Page) Freescale Semiconductor, Inc – On-chip programming firmware for use with host personal computer, Clock generator module (CGM)

English

English German Russian Spanish Italian Polish Chinese Japanese Korean French Portuguese	Language :

MC908MR16CFUE Datasheet, PDF (39/282 Pages) Freescale Semiconductor, Inc – On-chip programming firmware for use with host personal computer, Clock generator module (CGM)

◁

FLASH Memory (FLASH)

HVEN â High-Voltage Enable Bit

This read/write bit enables the charge pump to drive high voltages for program and erase operations

in the array. HVEN can only be set if either PGM = 1 or ERASE = 1 and the proper sequence for

program or erase is followed.

1 = High voltage enabled to array and charge pump on

0 = High voltage disabled to array and charge pump off

MASS â Mass Erase Control Bit

Setting this read/write bit configures the 32-Kbyte FLASH array for mass erase operation. Mass erase

is disabled if any FLASH block is protected

1 = MASS erase operation selected

0 = MASS erase operation unselected

ERASE â Erase Control Bit

This read/write bit configures the memory for erase operation. ERASE is interlocked with the PGM bit

such that both bits cannot be equal to 1 or set to 1 at the same time.

1 = Erase operation selected

0 = Erase operation unselected

PGM â Program Control Bit

This read/write bit configures the memory for program operation. PGM is interlocked with the ERASE

bit such that both bits cannot be equal to 1 or set to 1 at the same time.

1 = Program operation selected

0 = Program operation unselected

2.8.2 FLASH Page Erase Operation

Use this step-by-step procedure to erase a page (128 bytes) of FLASH memory.

1. Set the ERASE bit and clear the MASS bit in the FLASH control register.

2. Read the FLASH block protect register.

3. Write any data to any FLASH location within the address range of the block to be erased.

4. Wait for a time, tNVS (minimum 10 Âµs).

5. Set the HVEN bit.

6. Wait for a time, tErase (minimum 1 ms or 4 ms).

7. Clear the ERASE bit.

8. Wait for a time, tNVH (minimum 5 Âµs).

9. Clear the HVEN bit.

10. After time, tRCV (typical 1 Âµs), the memory can be accessed in read mode again.

NOTE

Programming and erasing of FLASH locations cannot be performed by

code being executed from the FLASH memory. While these operations

must be performed in the order shown, other unrelated operations may

occur between the steps.

In applications that require more than 1000 program/erase cycles, use the 4 ms page erase specification

to get improved long-term reliability. Any application can use this 4 ms page erase specification. However,

in applications where a FLASH location will be erased and reprogrammed less than 1000 times, and

speed is important, use the 1 ms page erase specification to get a shorter cycle time.

MC68HC908MR32 â¢ MC68HC908MR16 Data Sheet, Rev. 6.1

Freescale Semiconductor

39

▷