HD6432646 Hitachi, HD6432646 Datasheet - Page 691

• Manufacturer Part Number: HD6432646
• Description: (HD64F264x Series) 16-Bit Microcomputer
• Manufacturer: Hitachi

20.1
The LSI (H8S/2646R, H8S/2648R) has 128 kbytes of on-chip flash memory. 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 1 kB, 8 kB, 16 kB, 28 kB, and 32 kB blocks.
Programming/erase times
The flash memory programming time is 10 ms (typ.) for simultaneous 128-byte programming,
equivalent to 78 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 two protect modes, hardware and software, which allow protected status to be
designated for flash memory program/erase/verify operations.
Programmer mode
Flash memory can be programmed/erased in programmer mode, using a PROM programmer,
as well as in on-board programming mode.
Program mode
Erase mode
Program-verify mode
Erase-verify mode
Boot mode
User program mode
Features
Section 20 ROM
657