h8s-2635 Renesas Electronics Corporation., h8s-2635 Datasheet - Page 861

• Manufacturer Part Number: h8s-2635
• Description: Renesas 16-bit Single-chip Microcomputer H8s Family/h8s/2600 Series
• Manufacturer: Renesas Electronics Corporation.

21B.4 Flash Memory Overview
21B.4.1 Features
The H8S/2638 and H8S/2639 have 256 kbytes of on-chip flash memory, or 256 kbytes of on-chip
mask ROM. The H8S/2630 has 384 kbytes of on-chip flash memory, or 384 kbytes of on-chip
mask ROM. The features of the flash memory are summarized below.
Four flash memory operating modes
Programming/erase methods
The flash memory is programmed 128 bytes at a time. Block erase (in single-block units) can
be performed. To erase the entire flash memory, each block must be erased in turn. Block
erasing can be performed as required on 4 kbytes, 32 kbytes, and 64 kbytes blocks.
Programming/erase times
The flash memory programming time is 10 ms (typ.) for simultaneous 128-byte programming,
equivalent to 80 µs (typ.) per byte, and the erase time is 100 ms (typ.).
Reprogramming capability
The flash memory can be reprogrammed up to 100 times.
On-board programming modes
There are two modes in which flash memory can be programmed/erased/verified on-board:
Automatic bit rate adjustment
With data transfer in boot mode, the LSI’s bit rate can be automatically adjusted to match the
transfer bit rate of the host.
Flash memory emulation in RAM
Flash memory programming can be emulated in real time by overlapping a part of RAM onto
flash memory.
Protect modes
There are three protect modes, hardware, software, and error protection, which allow protected
status to be designated for flash memory program/erase/verify operations.
Program mode
Erase mode
Program-verify mode
Erase-verify mode
Boot mode
User program mode
Section 21B ROM (H8S/2638 Group, H8S/2639 Group, H8S/2630 Group)
Rev. 6.00 Feb 22, 2005 page 801 of 1484
REJ09B0103-0600