HD6433640 HITACHI [Hitachi Semiconductor], HD6433640 Datasheet - Page 114

• Manufacturer Part Number: HD6433640
• Description: H8/3644 Series Hardware Manual
• Manufacturer: HITACHI [Hitachi Semiconductor]

6.1
The H8/3644 has 32 kbytes of on-chip mask ROM, PROM or flash memory. The H8/3643 has 24
kbytes of mask ROM or flash memory. The H8/3642 has 16 kbytes of mask ROM or flash
memory. The H8/3641 has 12 kbytes of on-chip ROM. H8/3640 has 8 kbytes of ROM. The ROM
is connected to the CPU by a 16-bit data bus, allowing high-speed two-state access for both byte
data and word data.
In the PROM version (H8/3644 ZTAT) and flash memory versions (H8/3644 F-ZTAT, H8/3643
F-ZTAT, H8/3642 AF-ZTAT), programs can be written and erased with a general-purpose PROM
programmer. In the on-chip flash memory versions, programs can be written and erased on-board.
6.1.1
Figure 6.1 shows a block diagram of the on-chip ROM.
Overview
Block Diagram
H'7FFE
H'0000
H'0002
Figure 6.1 ROM Block Diagram (H8/3644)
Even-numbered
Internal data bus (upper 8 bits)
address
Internal data bus (lower 8 bits)
H'7FFE
H'0000
H'0002
Section 6 ROM
On-chip ROM
Odd-numbered
address
H'7FFF
H'0001
H'0003
105