Datasheet

Section 7 ROM
ROM3321A_000120030300 Rev. 3.00 Sep. 14, 2006 Page 97 of 408
REJ09B0105-0300
Section 7 ROM
The features of the 12-kbyte (including 4 kbytes as the E7 or E8 control program area) flash
memory built into the HD64F36912G and HD64F36902G are summarized below.
• Programming/erase methods
 The flash memory is programmed in 64-byte units at a time. Erase is performed in single-
block units. The flash memory is configured as follows: 1 kbyte × 4 blocks and 4 kbytes ×
2 blocks. To erase the entire flash memory, each block must be erased in turn.
• Reprogramming capability
 The flash memory can be reprogrammed up to 1,000 times.
• On-board programming
 On-board programming/erasing can be done in boot mode, in which the boot program built
into the chip is started to erase or program of the entire flash memory. In normal user
program mode, individual blocks can be erased or programmed.
• Automatic bit rate adjustment
 For data transfer in boot mode, this LSI's bit rate can be automatically adjusted to match
the transfer bit rate of the host.
• Programming/erasing protection
 Sets software protection against flash memory programming/erasing.
7.1 Block Configuration
Figure 7.1 shows the block configuration of 12-kbyte flash memory. The thick lines indicate
erasing units, the narrow lines indicate programming units, and the values are addresses. The flash
memory is divided into 1 kbyte × 4 blocks and 4 kbytes × 2 blocks. Erasing is performed in these
units. Programming is performed in 64-byte units starting from an address with lower eight bits
H'00, H'40, H'80, or H'C0.