HD6432670 Hitachi, HD6432670 Datasheet - Page 166

• Manufacturer Part Number: HD6432670
• Description: (HD64F267x Series) 16-Bit Microcomputer
• Manufacturer: Hitachi

A block diagram of the bus controller is shown in figure 6.1.
Rev. 2.0, 04/02, page 120 of 906
Legend
ABWCR
ASTCR
WTCRAH, WTCRAL,
WTCRBH, and WTCRBL : Wait control registers AH, AL, BH, and BL
RDNCR
CSACRH and CSACRL : CS assertion period control registers
BROMCRH
Note: * DRACCR is an 8-bit register in the H8S/2678 Series and a 16-bit register in the H8S/2678R Series.
EXDMAC address bus
Internal address bus
Internal bus master bus acknowledge signal
Internal bus master bus request signal
EXDMAC bus acknowledge signal
DMAC bus acknowledge signal
CPU bus acknowledge signal
DTC bus acknowledge signal
EXDMAC bus request signal
: Bus width control register
: Access state control register
: Read strobe timing control register
: Area 0 burst ROM interface control register
Internal bus control signals
DMAC bus request signal
CPU bus request signal
DTC bus request signal
Figure 6.1 Block Diagram of Bus Controller
Internal data bus
Address
selector
External bus
Internal bus
BROMCRH BROMCRL
External bus controller
Control registers
WTCRAH WTCRAL
WTCRBH WTCRBL
CSACRH
Internal bus controller
arbiter
arbiter
ABWCR
RDNCR
Area decoder
BROMCRL : Area 1 burst ROM interface control register
BCR
DRAMCR : DRAM control register
DRACCR : DRAM access control register
REFCR
RTCNT
RTCOR
BCR
CSACRL
ASTCR
: Bus control register
: Refresh control register
: Refresh timer counter
: Refresh time constant register
RTCNT
DRAMCR
DRACCR*
REFCR
External bus
control signals
to
RTCOR