M16C6KA_15 Datasheet, PDF (203/270 Pages) Renesas Technology Corp – SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER Description

M16C/6KA Group
Port
The P0, P1, P40 to P46, P11 and P14 output type, CMOS or N channel open drain, are set by bit 0 to 6 of port
control register 1 and bit 0 to 2 of port control register 3.
0 : CMOS output
1 : N channel open drain output
Exception: P42 output type is N channel open drain if either bit 4 of port control register 1 or bit 2 of port
control register 3 is set to “1”.
Bit 7 of port control register1 functions as below
0 : P40/P43 output is cleared by software only
1 : P40/P43 output is cleared by software or when output buffer 0 is read by host side.
The driving ability of N channel output transistors for P140 to P143 can be selected by bit 6 of port control
register 2 controls as below:
0 : Driving ability of N channel open drain output transistor is LOW
1 : Driving ability of N channel open drain output transistor is HIGH
(5) Port P4/P7 input register
Fig.UA-14 shows the configurations of P4 and P7 input register.
By reading the registers, the input level of the corresponding pins can be known regardless the input/output
mode. These two registers can be read regardless port direction setting. And the ports level will be read out.
Port4 : Bit 0 to bit6's level will be read out. And bit7 is always “0”.
Port7 : Bit 0 to bit5's level will be read out. And bit6,7 is always “0”.
(6) Port function selection register 0,1,2
Fig.UA-15, UA-16 shows the configurations of port function selection register 0,1. The port functions of
________ __________
UART1 input/output, TimerA0 to TimerA2 output, TimerB3,B4 input, external interrupt INT6 to INT12 input or
I²C1,2 input/output can be switched by setting these two registers.
By setting bit0,1 of port function selection register 2, the same frequency clock with f(XIN) can be output from
P110 and P111.
Rev.1.00 Jul 16, 2004 page 201 of 266
REJ03B0100-0100Z