HD6432646 Hitachi, HD6432646 Datasheet - Page 110

• Manufacturer Part Number: HD6432646
• Description: (HD64F264x Series) 16-Bit Microcomputer
• Manufacturer: Hitachi

2.9.5
The external address space is accessed with an 8-bit or 16-bit data bus width in a two-state or
three-state bus cycle. In three-state access, wait states can be inserted. For further details, refer to
section 7, Bus Controller.
2.10
2.10.1
Only register ER0, ER1, ER4, or ER5 should be used when using the TAS instruction. The TAS
instruction is not generated by the Hitachi H8S and H8/300 series C/C++ compilers. If the TAS
instruction is used as a user-defined intrinsic function, ensure that only register ER0, ER1, ER4, or
ER5 is used.
2.10.2
The BSET, BCLR, BNOT, BST and BIST instructions read data in a unit of byte, then, after bit
manipulation, they write data in a unit of byte. Therefore, caution must be exercised when
executing any of these instructions for registers and ports that include write-only bits.
76
External Address Space Access Timing
Usage Note
TAS Instruction
Caution to observe when using bit manipulation instructions
ø
Address bus
AS
RD
HWR, LWR
Data bus
Figure 2-23 Pin States in On-Chip HCAN Module Access
T1
High-impedance state
T2
Bus cycle
Held
High
High
High
T3
T4