HD6417615 Hitachi Semiconductor, HD6417615 Datasheet - Page 271

• Manufacturer Part Number: HD6417615
• Description: Hardware Manual
• Manufacturer: Hitachi Semiconductor

7.1.4
The BSC has seven registers. These registers are used to control wait states, bus width, interfaces
with memories like DRAM, synchronous DRAM, and burst ROM, and DRAM and synchronous
DRAM refreshing. The register configurations are shown in table 7.2.
The size of the registers themselves is 16 bits. If read as 32 bits, the upper 16 bits are 0. In order to
prevent writing mistakes, 32-bit writes are accepted only when the value of the upper 16 bits of the
write data is H'A55A; no other writes are performed. Initialize the reserved bits.
Initialization Procedure: Do not access a space other than CS0 until the settings for the interface
to memory are completed.
Table 7.2
Name
Bus control register 1
Bus control register 2
Bus control register 3
Wait control register 1
Wait control register 2
Wait control register 3
Individual memory control register
Refresh timer control/status register RTCSR
Refresh timer counter
Refresh time constant register
Notes: 1. This address is for 32-bit accesses; for 16-bit accesses add 2.
254
2. 16-bit access is for read only.
Register Configuration
Register Configuration
Abbr.
BCR1
BCR2
BCR3
WCR1
WCR2
WCR3
MCR
RTCNT
RTCOR
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
Initial Value Address*
H'03F0
H'00FC
H'0F00
H'AAFF
H'000B
H'0000
H'0000
H'0000
H'0000
H'0000
H'FFFFFFE0 16*
H'FFFFFFE4 16*
H'FFFFFFFC 16*
H'FFFFFFE8 16*
H'FFFFFFC0 16*
H'FFFFFFC4 16*
H'FFFFFFEC 16*
H'FFFFFFF0 16*
H'FFFFFFF4 16*
H'FFFFFFF8 16*
1
Access Size
2
2
2
2
2
2
2
2
2
2
, 32
, 32
, 32
, 32
, 32
, 32
, 32
, 32
, 32
, 32