SH7727 Datasheet, PDF (395/1109 Pages) Renesas Technology Corp – Renesas 32-Bit RISC Microcomputer SuperH RISC engine Family/SH7700 Series

Section 12 Bus State Controller (BSC)
When synchronous DRAM is connected, the RAS3 signal, CAS signal, RD/WR signal, and byte
controls DQMHH, DQMHL, DQMLH, and DQMLL are all asserted and addresses multiplexed.
Control of RAS3, CAS, data timing, and address multiplexing is set with MCR.
Area 3: Area 3 physical addresses A28 to A26 are 011. Addresses A31 to A29 are ignored and the
address range is H'0C000000 + H'20000000 × n to H'0FFFFFFF + H'20000000 × n (n = 0 to 6 and
n = 1 to 6 are the shadow spaces).
Ordinary memories like SRAM and ROM, as well as synchronous DRAM, can be connected to
this space. Byte, word or longword can be selected as the bus width using the A3SZ1 to A3SZ0
bits of BCR2 for ordinary memory. When area 3 space is accessed, CS3 is asserted.
When ordinary memories are connected, an RD signal that can be used as OE and the WE0 to
WE3 signals for write control are asserted and the number of bus cycles is selected between 0 and
3 wait cycles using the A3W1 to A3W0 bits of WCR2. In addition, any number of waits can be
inserted in each bus cycle by means of the external wait pin (WAIT).only when the ordinary
memories are connected.
When synchronous DRAM is connected, the RAS3 signal, CAS signal, RD/WR signal, and byte
controls DQMHH, DQMHL, DQMLH, and DQMLL are all asserted and addresses multiplexed.
Area 4: Area 4 physical addresses A28 to A26 are 1'0. AddressesA31 to A29 are ignored and the
address range is H'10000000 + H'20000000 × n – H'13FFFFFF + H'20000000 × n (n = 0 to 6 and
n = 1 to 6 are the shadow spaces).
Only ordinary memories like SRAM and ROM can be connected to this space. Byte, word, or
longword can be selected as the bus width using the A4SZ1 to A4SZ0 bits of BCR2. When the
area 4 space is accessed, a CS4 signal is asserted. An RD signal that can be used as OE and the
WE0 to WE3 signals for write control are also asserted. The number of bus cycles is selected
between 0 and 10 wait cycles using the A4W2 to A4W0 bits of WCR2. In addition, any number
of waits can be inserted in each bus cycle by means of the external wait pin (WAIT).
Area 5: Area 5 physical addresses A28 to A26 are 101. Addresses A31 to A29 are ignored and the
address range is the 64 Mbytes at H'14000000 + H'20000000 × n to H'17FFFFFF + H'20000000 ×
n (n = 0 to 6 and n = 1 to 6 are the shadow spaces).
Ordinary memories like SRAM and ROM as well as burst ROM and PCMCIA interfaces can be
connected to this space. When the PCMCIA interface is used, the IC memory card interface
address range-comprises the 32 Mbytes at H'14000000 + H'20000000 × n to H'15FFFFFF +
H'20000000 × n (n = 0 to 6 and n = 1 to 6 are the shadow spaces), and the I/O card interface
address range-comprises the 32 Mbytes at H'16000000 + H'20000000 × n to H'17FFFFFF +
H'20000000 × n (n = 0 to 6 and n = 1 to 6 are the shadow spaces).
Rev. 5.00 Dec 12, 2005 page 323 of 1034
REJ09B0254-0500