tmp89fm42 TOSHIBA Semiconductor CORPORATION, tmp89fm42 Datasheet - Page 103

• Manufacturer Part Number: tmp89fm42
• Description: 8 Bit Microcontroller
• Manufacturer: TOSHIBA Semiconductor CORPORATION

RA005
8. I/O Ports
Table 8-1 List of I/O Ports
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 out-
put to an I/O port in the next cycle of the write cycle during execution of the write instruction.
Port name
Note: P00 and P01 pins can not be used for the I/O port, because they should be connected with the high frequency OSC
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.
Port P0
Port P1
Port P2
Port P4
Port P7
Port P8
Port P9
Port PB
input.
Internal read
signal
Data input
Internal write
signal
Data input
System clock
Instruction
execution cycle
System clock
Instruction
execution cycle
PB7 to PB4
P03 to P00
P13 to P10
P27 to P20
P47 to P40
P77 to P70
P81 to P80
P91 to P90
Pin name
(Note)
Figure 8-1 Input/Output Timing (Example)
Number of pins
(Note)
Fetch cycle
Fetch cycle
4
4
8
8
8
2
2
4
Example: LD A, (x)
Example: LD (x), A
Input/output
Input/output
Input/output
Input/output
Input/output
Input/output
Input/output
Input/output
Input/output
Fetch cycle
Fetch cycle
Page 89
(a) Input timing
(b) Input timing
Also used as the high-frequency oscillator connection pin and the
low-frequency oscillator connection pin
Also used as the external reset input, the external interrupt input and
the STOP mode release signal input
Also used as the UART input/output, the serial interface input/output
and the serial bus interface input/output
Also used as the analog input and the key-on wakeup input
Also used as the timer counter input/output, the divider output and
the external interrupt input
Also used as the timer counter input/output
Also used as the UART input/output
Also used as the UART input/output and the serial interface input/out-
put
Read cycle
Write cycle
Secondary functions
TMP89FM42