HD6417021 Hitachi Semiconductor, HD6417021 Datasheet - Page 169

• Manufacturer Part Number: HD6417021
• Description: SuperH RISC engine
• Manufacturer: Hitachi Semiconductor

8.6.2
When the address/data multiplexed I/O space is accessed, the WAIT pin input signal is sampled
and a wait state inserted whenever a low level is detected, regardless of the setting of the WCR.
Figure 8.33 shows an example in which a WAIT signal causes a wait state of 1 state to be inserted.
8.6.3
The byte access control signals when the address/data multiplexed I/O space is being accessed are
of two types (WRH, WRL, A0, or WR, HBS, LBS), just as for byte access control of external
memory space access. These types can be selected using the BAS bit of the BCR. See section
8.4.3, Byte Access Control, for details.
Read
Write
Figure 8.33 Wait State Timing For Address/Data Multiplexed I/O Space Access
Wait State Control
Byte Access Control
WRH, WRL
AD15–AD0
AD15–AD0
A21–A0
WAIT
RD
CK
CS
AH
T1
Address
Address
T2
T3
(wait state)
Tw
Data (output)
Data (input)
T4
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