NEC V850E/MA1 User Manual page 51

(5) P40 to P45 (Port 4) ··· 3-state I/O
P40 to P45 function as a 6-bit I/O port that can be set to input or output in 1-bit units.
Besides functioning as an I/O port, in the control mode, these pins operate as I/O for the serial interfaces
(UART0/CSI0, UART1/CSI1).
The operation mode can be set to port or control mode in 1-bit units, specified by the port 4 mode control
register (PMC4).
(a) Port mode
P40 to P45 can be set to input or output in 1-bit units using the port 4 mode register (PM4).
(b) Control mode
P40 to P45 can be set to port/control mode in 1-bit units using the PMC4 register.
(i) TXD0, TXD1 (Transmit data) ··· output
These pins output UART0, UART1 serial transmit data.
(ii) RXD0, RXD1 (Receive data) ··· input
These pins input UART0, UART1 serial receive data.
(iii) SO0, SO1 (Serial output) ··· output
These pins output CSI0, CSI1 serial transmit data.
(iv) SI0, SI1 (Serial input) ··· input
These pins input CSI0, CSI1 serial receive data.
(v) SCK0, SCK1 (Serial clock) ··· 3-state I/O
These are the CSI0, CSI1 serial clock I/O pins.
CHAPTER 2 PIN FUNCTIONS
User's Manual U14359EJ4V0UM
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