Renesas H8SX/1650, Руководство по оборудованию

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Section 6 Bus Controller (BSC)
Rev.2.00 Jun. 28, 2007 Page 121 of 666
REJ09B0311-0200
Section 6 Bus Controller (BSC)
This LSI has an on-chip bus controller (BSC) that manages the external address space divided into
eight areas.
The bus controller also has a bus arbitration function, and controls the operation of the internal bus
masters; CPU and DTC.
6.1 Features
•
Manages external address space in area units
Manages the external address space divided into eight areas.
Chip select signals (
CS0
to
CS7
) can be output for each area.
Bus specifications can be set independently for each area.
8-bit access or 16-bit access can be selected for each area.
Burst ROM, byte control SRAM, or address/data multiplexed I/O interface can be set.
An endian conversion function is provided to connect a device of little endian.
•
Basic bus interface
This interface can be connected to the SRAM and ROM.
2-state access or 3-state access can be selected for each area.
Program wait cycles can be inserted for each area.
Wait cycles can be inserted by the
WAIT
pin.
Extension cycles can be inserted while
CSn
is asserted for each area (n = 0 to 7).
The negation timing of the read strobe signal (
RD
) can be modified.
•
Byte control SRAM interface
Byte control SRAM interface can be set for areas 0 to 7.
The SRAM that has a byte control pin can be directly connected.
•
Burst ROM interface
Burst ROM interface can be set for areas 0 and 1.
Burst ROM interface parameters can be set independently for areas 0 and 1.
•
Address/data multiplexed I/O interface
Address/data multiplexed I/O interface can be set for areas 3 to 7.