IBM EM78P259N/260N manual External Reference Signal, Comparator Output

EM78P259N/260N

8-Bit Microprocessor with OTP ROM

6.10.1 External Reference Signal

The analog signal that is presented at Cin– compares to the signal at Cin+. The digital output (CO) of the comparator is adjusted accordingly by taking the following notes into considerations:

NOTE

■The reference signal must be between Vss and Vdd.

■The reference voltage can be applied to either pin of the comparator.

■Threshold detector applications may be of the same reference.

■The comparator can operate from the same or different reference sources.

6.10.2 Comparator Output

„The compared result is stored in the CMPOUT of IOC80.

„The comparator outputs are sent to CO (P64) through programming Bit 4 &

Bit 3<COS1, COS0> of the IOC80 register to <1,0>. See table under Section 6.2.4, IOC80 (Comparator and TCCA Control Registers) for Comparator/OP select bits function description.

The following figure shows the Comparator Output block diagram.

To C0
			From OP I/O
			CMRD
	EN		EN
Q	D	Q	D
To CMPOUT
RESET
			To CPIF
CMRD
		From other
		comparator

Fig. 6-15 Comparator Output Configuration

Product Specification (V1.2) 05.18.2007 • 59

(This specification is subject to change without further notice)