Am8253 Control Byte Format; Am8253 Control Byte Definition - Advanced Micro Computers Am96/4016 User Manual

TABU: 5-9. Am8253 CONTROL BYTE FORMAT
TABLE !i-10. Am8253 CONTROL BYTE DEFINITION
SCI sea
a
a
1
- - -
I
a
1
a
1
RLI RLa
a
a
Counter Latching
operation
~-----f--
1 a Read/Load most sig-
nificant byte only.
r-------f--
a 1 Read/Load least sig-
nificant byte only.
r-------f--
1 1 Read/Load least sig-
nificant byte first,
than most significant
byte .. _.
M2
MI
Ma
a
0
a Mode a
a
0
1 Mode 1
-
X
1
a Mode 2
-
X
1 1 Mode 3
1
0
a Mode 4
_.-
1 a
1
Mode 5
a Binary Counter 16-bits
1 Binary Coded Decimal (BCD)
Counter (4 Decades)
5-9