HD6433644R datasheet(180/549 Pages) RENESAS

180 / 549 page

Section 6 ROM

Rev. 6.00 Sep 12, 2006 page 160 of 526

REJ09B0326-0600

6.9

Flash Memory Programming and Erasing Precautions

Precautions concerning the use of on-board programming modes and PROM mode are

summarized below.

1. Program with the specified voltages and timing.

The rated programming voltage (VPP) of the flash memory is 12.0 V.

If the PROM programmer is set to Renesas HN28F101 specifications, VPP will be 12.0 V.

Applied voltages in excess of the rating can permanently damage the device. In particular,

insure that the peak overshoot of the PROM programmer does not exceed the maximum rating

of 13 V.

2. Before programming, check that the chip is correctly mounted in the PROM programmer.

Overcurrent damage to the device can result if the index marks on the PROM programmer

socket, socket adapter, and chip are not correctly aligned.

3. Do not touch the socket adapter or chip while programming. Touching either of these can

cause contact faults and write errors.

4. Set H'FF as the PROM programmer buffer data for the following addresses:

H8/3644F: H'8000 to H'1FFFF

H8/3643F: H'6000 to H'1FFFF

H8/3642AF: H'4000 to H'1FFFF

The size of the PROM area is 32 kbytes in the H8/3644F, 24 kbytes in the H8/3643F, and 16

kbytes in the H8/3642AF. The addresses shown above always read H'FF, so if H'FF is not

specified as programmer data, a block error will occur.

5. Precautions in applying, releasing, and cutting*1 the programming voltage (VPP)

a. Apply the programming voltage (VPP) after VCC has stabilized, and release VPP before

cutting VCC.

To avoid programming or erasing flash memory by mistake, VPP should only be applied,

released, and cut when the MCU is in a “stable operating condition” as described below.

MCU stable operating condition

• The VCC voltage must be within the rated voltage range (VCC = 2.7 V to 5.5 V).

If the VPP voltage is applied, released, or cut while VCC is not within its rated voltage

range (VCC = 2.7 V to 5.5 V), since the MCU is unstable, the flash memory may be

programmed or erased by mistake. This can occur even if VCC = 0 V. Adequate power

supply measures should be taken, such as the insertion of a bypass capacitor, to prevent

fluctuation of the VCC power supply when VPP is applied.

HD6433644R Datasheet(PDF) 180 Page - Renesas Technology Corp