Valid Strobes - Renesas H8S Series Hardware Manual

6.4.3

Valid Strobes

Table 6-4 shows the data buses used and valid strobes for the access spaces.
In a read, the RD signal is valid without discrimination between the upper and lower halves of the data bus.
In a write, the HWR signal is valid for the upper half of the data bus, and the LWR signal for the lower half.
Table 6-4 Data Buses Used and Valid Strobes
Area
8-bit access
space
16-bit access Byte
space
Legend:
Hi-Z: High impedance
Invalid: Input state; input value is ignored.
Access Read/
Size Write Address
Byte Read —
Write —
Read Even
Odd
Write Even
Odd
Word Read —
Write —
Valid Upper Data Bus
Strobe (D to D )
15 8
RD
Valid
HWR
RD
Valid
Invalid
HWR
Valid
LWR
Hi-Z
RD
Valid
HWR, LWR Valid
Lower data bus
(D to D )
7 0
Invalid
Hi-Z
Invalid
Valid
Hi-Z
Valid
Valid
Valid
Rev.6.00 Oct.28.2004 page 127 of 1016
REJ09B0138-0600H