HD6413007F20 Datasheet, PDF (573/798 Pages) Renesas Technology Corp – Hardware Manual Renesas 16-Bit Single-Chip Microcomputer H8 Family/H8/300H Series

Section 17 RAM
17. RAM
17.1 Overview
The H8/3007 has 4 kbytes of high-speed static RAM on-chip. The H8/3006 has 2 kbytes. The
RAM is connected to the CPU by a 16-bit data bus. The CPU accesses both byte data and word
data in two states, making the RAM useful for rapid data transfer.
The on-chip RAM of the H8/3007 is assigned to addresses H'FEF20 to H'FFF1F in modes 1 and 2,
and to addresses H'FFEF20 to H'FFFF1F in modes 3 and 4. The on-chip RAM of the H8/3006 are
assigned to addresses H'FF720 to H'FFF1F in modes 1 and 2, and to addresses H'FFF720 to
H'FFFF1F in modes 3 and 4. The RAM enable bit (RAME) in the system control register
(SYSCR) can enable or disable the on-chip RAM.
17.1.1 Block Diagram
Figure 17.1 shows a block diagram of the on-chip RAM.
On-chip data bus (upper 8 bits)
On-chip data bus (lower 8 bits)
Bus interface
SYSCR
H'FEF20*
H'FEF22*
H'FEF21*
H'FEF23*
On-chip RAM
H'FFF1E*
Even addresses
Legend:
SYSCR: System control register
H'FFF1F*
Odd addresses
Note: * This example is of the H8/3007 operating in mode 1 and 2. The lower 20 bits of the address
are shown.
Figure 17.1 RAM Block Diagram
Rev.5.00 Sep. 12, 2007 Page 543 of 764
REJ09B0396-0500