User guide

100 Appendix
Control Byte: (Base + 7, Base + 11)
X SC1 & SC1 - Select Counter (Bit7 & Bit 6)
X RL1 & RL0 - Select Read/Load operation (Bit 5 & Bit 4)
X M2, M1 & M0 - Select Operating Mode (Bit 3, Bit 2, & Bit 1)
X BCD - Select Binary/BCD Counting (Bit 0)
Note:
1. The count of the binary counter is from 0 up to 65,535.
Bit 7 6 5 4 3 2 1 0
SC1 SC0 RL1 RL0 M2 M1 M0 BCD
SC1 SC0 COUNTER
00 0
01 1
10 2
1 1 ILLEGAL
RL1 RL0 OPERATION
0 0 COUNTER LATCH
0 1 READ/LOAD LSB
1 0 READ/LOAD MSB
1 1 READ/LOAD LSB FIRST, THEN MSB
M2 M1 M0 MODE
000 0
001 1
x10 2
x11 3
100 4
101 5
0 BINARY COUNTER 16-BITS
1 BINARY CODED DECIMAL (BCD) COUNTER (4 DECADES)