Table of Contents
Advertisement
6. ROM
6.2
Overview of Flash Memory
6.2.1
Features
Features of the flash memory are summarized below.
• Four flash memory operating modes
⎯ Program mode
⎯ Erase mode
⎯ Program-verify mode
⎯ Erase-verify mode
• Programming/erase methods
The flash memory is programmed 32 bytes at a time. Erasing is performed in block units. To
erase multiple blocks, each block must be erased in turn. In block erasing, 1-kbyte, 28-kbyte,
16-kbyte, and 12-kbyte blocks can be set arbitrarily.
• Programming/erase times
The flash memory programming time is 10 ms (typ.)*
equivalent to 300 μs (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:
⎯ Boot mode
⎯ 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 (9600, 4800, or 2400 bps).
• Protect modes
There are three protect modes⎯hardware, software, and error⎯which allow protected status
to be designated for flash memory program/erase/verify operations.
• Writer mode
Flash memory can be programmed/erased in Writer mode, using a PROM programmer, as well
as in on-board programming mode.
Notes: 1. Shows the total time during which the P bit in flash memory control register 1
(FLMCR1) is set. The program-verify time is not included.
2. Shows the total time during which the E bit in flash memory control register 1
(FLMCR1) is set. The erase-verify time is not included.
Rev.3.00 Jul. 19, 2007 page 120 of 532
REJ09B0397-0300
1
per byte, and the erase time is 100 ms (typ.)*
1
for simultaneous 32-byte programming,
2
per block.
Advertisement
Table of Contents
