r4f2426 Renesas Electronics Corporation., r4f2426 Datasheet - Page 231

• Manufacturer Part Number: r4f2426
• Description: 16-bit Single-chip Microcomputer H8s Family / H8s/2400 Series
• Manufacturer: Renesas Electronics Corporation.

6.6.3
The bus width of the address/data multiplexed I/O space can be specified for either 8-bit access
space or 16-bit access space by the ABW7 and ABW6 bits in ABWCRA. For the 8-bit access
space, D15 to D8 are valid for both address and data. For the 16-bit access space, D15 to D0 are
valid for both address and data. If the address/data multiplexed I/O space is accessed, the
corresponding address will be output to the address bus. For details on access size and data
alignment, see section 6.5.1, Data Size and Data Alignment.
6.6.4
In the address/data multiplexed I/O space, a hold signal (AH) that indicates the timing for latching
the address is output. The AH output pin is multiplexed with the AS output pin. When the external
address space is specified as the address/data multiplexed I/O space, the multiplexed pin functions
as the AH output pin. Note however that the multiplexed pin will function as the AS output pin
until the address/data multiplexed I/O space is specified.
6.6.5
The bus cycle in the address/data multiplexed I/O interface consists of an address cycle and a data
cycle. The data cycle is based on the basic bus interface timing specified by ABWCR, ASTCR,
WTCRAH, RDNCR, and CSACR.
Data Bus
Address Hold Signal
Basic Timing
Rev. 1.00 Sep. 19, 2008 Page 203 of 1270
Section 6 Bus Controller (BSC)
REJ09B0466-0100