tmp89ch42 TOSHIBA Semiconductor CORPORATION, tmp89ch42 Datasheet - Page 104

• Manufacturer Part Number: tmp89ch42
• Description: 8 Bit Microcontroller Tlcs-870/c1 Series
• Manufacturer: TOSHIBA Semiconductor CORPORATION

RA007
should be externally held until the input data is read from outside or reading should be performed several times before
processing. Figure 8-1 shows input/output timing examples.
be recognized from outside, so that transient input such as chattering must be processed by the program. Data is output
to an I/O port in the next cycle of the write cycle during execution of the write instruction.
Each output port contains a latch, which holds the output data. No input port has a latch, so the external input data
External data is read from an I/O port in the read cycle during execution of the read instruction. This timing cannot
Note:The positions of the read and write cycles may vary, depending on the instruction.
Internal read
signal
Data input
Internal write
signal
Data output
System clock
Instruction
execution cycle
System clock
Instruction
execution cycle
Figure 8-1 Input/Output Timing (Example)
Fetch cycle
Fetch cycle
Example: LD A, (x)
Example: LD (x), A
Fetch cycle
Fetch cycle
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(a) Input timing
(b) Output timing
Read cycle
Write cycle
TMP89CH42