IBM EM78P259N/260N manual 3 IOC50 ~ IOC70 I/O Port Control Register, Bit 7 & Bit 6 Not used

EM78P259N/260N

8-Bit Microprocessor with OTP ROM

Bit 2 ~ Bit 0 (PST2 ~ PST0): TCC prescaler bits

PST2	PST1	PST0
0	0	0
0	0	1
0	1	0
0	1	1
1	0	0
1	0	1
1	1	0
1	1	1

TCC Rate

1:2

1:4

1:8

1:16

1:32

1:64

1:128

1:256

Note: Tcc time-out period [1/Fosc x prescaler x 256 (Tcc cnt) x 1 (CLK=2)]

Tcc time-out period [1/Fosc x prescaler x 256 (Tcc cnt) x 2 (CLK=4)]

6.2.3 IOC50 ~ IOC70 (I/O Port Control Register)

„"1" puts the relative I/O pin into high impedance, while "0" defines the relative I/O pin as output.

„Only the lower 6 bits of IOC50 can be defined (this applies to EM78P259N only, since EM78P260N can use all the bits).

„Only the lower 1 bit of IOC70 can be defined, the other bits are not available.

„IOC50, IOC60, and IOC70 registers are all readable and writable

6.2.4 IOC80 (Comparator and TCCA Control Register)

Bit 7	Bit 6	Bit 5	Bit 4	Bit 3	Bit 2	Bit 1	Bit 0
–	–	CMPOUT	COS1	COS0	TCCAEN	TCCATS	TCCATE

Note: Bits 4~0 of the IOC80 register are both readable and writable

Bit 5 of the IOC80 register is read only.

Bit 7 & Bit 6: Not used

Bit 5 (CMPOUT): Result of the comparator output

			This bit is read only.
	Bit 4 & Bit 3 (COS1 & COS0): Comparator/OP Select bits
	COS1	COS0		Function Description
	0	0		Comparator and OP are not used. P64, P65, and P66 function as
				normal I/O pins.
	0	1		Acts as Comparator and P64 functions as normal I/O pin
	1	0		Acts as Comparator and P64 functions as Comparator output pin (CO)
	1	1		Acts as OP and P64 functions as OP output pin (CO)
	Bit 2 (TCCAEN):		TCCA enable bit
			0 = disable TCCA
			1 = enable TCCA as a counter
16 •				Product Specification (V1.2) 05.18.2007
				(This specification is subject to change without further notice)