SH7080_09 Datasheet, PDF (357/1622 Pages) Renesas Technology Corp – Renesas 32-Bit RISC Microcomputer SuperH RISC engine Family

Section 9 Bus State Controller (BSC)
9.5.5 MPX-I/O Interface
Access timing for the MPX space is shown below. In the MPX space, CSn, AH, RD, and WRxx
signals control the accessing. The basic access for the MPX space consists of 2 cycles of address
output followed by an access to a normal space. The bus width for the address output cycle or the
data input/output cycle is fixed to 8 bits or 16 bits. Alternatively, it can be 8 bits or 16 bits
depending on the address to be accessed.
Output of the addresses D15 to D0 or D7 to D0 is performed from cycle Ta2 to cycle Ta3.
Because cycle Ta1 has a high-impedance state, collisions of addresses and data can be avoided
without inserting idle cycles, even in continuous accesses. Address output is increased to 3 cycles
by setting the MPXW bit in the CS5WCR register to 1. The RDWR signal is output at the same
time as the CSn signal; it is high in the read cycle and low in the write cycle.
The data cycle is the same as that in a normal space access.
Timing charts are shown in figures 9.11 to 9.13.
Note that the operation timing of the MPX-I/O interface differs between the SH7080 group and
the SH7040. For example, the AH signal is negated (high-level) in the SH7080 group and asserted
(low-level) in the SH7040 group during access to other than MPX-I/O space.
Rev. 4.00 Dec. 15, 2009 Page 297 of 1558
REJ09B0181-0400