Renesas SH7641 - Manual (Page 432)

Section 12 Bus State Controller (BSC)
Rev. 4.00 Sep. 14, 2005 Page 382 of 982
REJ09B0023-0400
12.5.9 Burst MPX-I/O Interface
Figure 12.42 shows an example of a connection between the LSI and an MPX device. Figures
12.43 to 12.46 show the burst MPX space access timings.
Area 6 can be specified as the address/data multiplex I/O (MPX-I/O) interface using the TYPE2 to
TYPE0 bits in the CS6BCR register. This MPX-I/O interface enables the LSI to be easily
connected to an external memory controller chip that uses an address/data multiplexed 32-bit
single bus. In this case, the address and the access size for the MPX-I/O interface are output to
D25 to D0 and D31 to D29, respectively, in address cycles. For the access sizes of D31 to D29,
see the description of the CS6BWCR register (burst MPX-I/O). Address pins A25 to A0 are used
to output normal addresses.
In the burst MPX-I/O interface, the bus size is fixed at 32 bits. The BSZ1 and BSZ0 bits in
CS6BBCR must be specified as 32 bits.
In the MPX-I/O interface, a software wait or hardware wait can be inserted using the
WAIT pin.
In read cycles, a wait cycle is inserted automatically following the address output even if the
software wait insertion is specified as 0.
This LSI
CS
BS
FRAME
WE
I/O31
I/O0
WAIT
CS6B
BS
FRAME
RD/ WR
D31
D0
WAIT
64k × 16-bit
SRAM
Figure 12.42 Burst MPX Device Connection Example