HD6433644R datasheet(132/549 Pages) RENESAS

132 / 549 page

Section 6 ROM

Rev. 6.00 Sep 12, 2006 page 112 of 526

REJ09B0326-0600

6.4.2

Mode Pin Settings and ROM Space

The H8/3644F has 32 kbytes of on-chip flash memory, the H8/3643F has 24 kbytes, and the

H8/3642AF has 16 kbytes. The ROM is connected to the CPU by a 16-bit data bus. The CPU

accesses flash memory in two states for both byte-size and word-size instructions.

The flash memory is allocated to addresses H'0000 to H'7FFF in the H8/3644F, to addresses

H'0000 to H'5FFF in the H8/3643F, and to addresses H'0000 to H'3FFF in the H8/3642AF.

6.4.3

Features

The features of the flash memory are summarized below.

• Five flash memory operating modes

There are five flash memory operating modes: program mode, program-verify mode, erase

mode, erase-verify mode, and prewrite-verify mode.

• Erase block specification

Blocks to be erased in the flash memory space can be specified by setting the corresponding

kbytes to 8 kbytes) and a small block area (eight blocks with sizes from 128 bytes to 1 kbyte).

• Programming/erase times

The flash memory programming time is 50 µs (typ.) per byte, and the erase time is 1 s (typ.).

• Erase-program cycles

Flash memory contents can be erased and reprogrammed up to 100 times.

• On-board programming modes

There are two modes in which flash memory can be programmed, erased, and verified on-

board: boot mode and user program mode.

• Automatic bit rate adjustment

For data transfer in boot mode, the chip’s bit rate can be automatically adjusted to match the

transfer bit rate of the host (max. 9600 bps).

• PROM mode

Flash memory can be programmed and erased in PROM mode, using a general-purpose PROM

programmer, as well as in on-board programming mode. The specifications for programming,

erasing, verifying, etc., are the same as for standard HN28F101 flash memory.

HD6433644R Datasheet(PDF) 132 Page - Renesas Technology Corp