TMP88FW45FG Datasheet, PDF (260/276 Pages) Toshiba Semiconductor – 8 Bit Microcontroller

20. Serial PROM Mode
20.14 Port Input Control Register
TMP88FW45FG
20.14Port Input Control Register
In the serial PROM mode, the input level is fixed to the all ports except P45 and P44 ports with a hardware feature
to prevent overlap current to unused ports. (All port inputs and peripheral function inputs shared with the ports
become invalid.) Therefore, to access to the flash memory in the RAM loader mode without UART communication,
port inputs must be valid. To make port inputs valid, set the pin of the port input control register (SPCR) to “1”.
The SPCR register is not operated in the MCU mode.
Port Input Control Register
SPCR
7
6
5
4
3
2
1
0
(0FEAH)
PIN
(Initial value: **** ***0)
Port input control in the serial PROM
0 : Invalid port inputs (The input level is fixed with a hardware feature.)
PIN
R/W
mode
1 : Valid port inputs
Note 1: The SPCR register can be read or written only in the serial PROM mode. When the write instruction is executed to the
SPCR register in the MCU mode, the port input control can not be performed. When the read instruction is executed for
the SPCR register in the MCU mode, read data of bit7 to 1 are unstable.
Note 2: All I/O ports except P45 and P44 ports are controlled by the SPCR register.
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