Athena III User Manual Rev A.03
www.diamondsystems.com
Page
56
12.2.1
Page 0: Counter / Timer Control
Page 0, Base + 12
Read/Write
Counter/Timer D7 - 0
Bit No.
7
6
5
4
3
2
1
0
Name
CTRD7
CTRD6
CTRD5
CTRD4
CTRD3
CTRD2
CTRD1
CTRD0
Reset
0
0
0
0
0
0
0
0
This register is used for both Counter 0 and Counter 1. It is the LSB for both counters.
When writing to this register, an internal load register is loaded. Upon issuing a Load command through Base +
15, the selected counter’s LSB register will be loaded with this value. When reading from this register, the LSB
value of the most recent Latch command will be returned. The value returned is NOT the value written to this
register.
Page 0, Base + 13
Read/Write
Counter/Timer D15 - 8
Bit No.
7
6
5
4
3
2
1
0
Name
CTRD15 CTRD14 CTRD13 CTRD12 CTRD11 CTRD10
CTRD9
CTRD8
Reset
0
0
0
0
0
0
0
0
This register is used for both Counter 0 and Counter 1. It is the MSB for counter 1 and the middle byte for counter
0.
When writing to this register, an internal load register is loaded. Upon issuing a Load command through Base +
15, the selected counter’s associated register will be loaded with this value. For counter 0, it is the middle byte.
For counter 1, it is the MSB.
When reading from this register, the associated byte of the most recent Latch command will be returned. The
value returned is NOT the value written to this register.
Page 0, Base + 14
Read/Write
Counter/Timer D23 - 16
Bit No.
7
6
5
4
3
2
1
0
Name
CTRD23 CTRD22 CTRD21 CTRD20 CTRD19 CTRD18 CTRD17 CTRD16
Reset
0
0
0
0
0
0
0
0
This register is used for Counter 0 only. Counter 0 is 24 bits wide, while Counter 1 is only 16 bits wide.
When writing to this register, an internal load register is loaded. Upon issuing a Load command through Base +
15 for Counter 0, the counter’s MSB register will be loaded with this value. When issuing a Load command for
counter 1, this register is ignored.
When reading from this register, the MSB value of the most recent Latch command for counter 0 will be returned.
The value returned is NOT the value written to this register.