10
AVR1306
4.1 16-bit Read
Figure 4-1 illustrates how to perform a 16-bit read of CNT, and what happens
internally:
1. Read CNTL. This will cause the contents of CNTH to be transferred to TEMP in the
same clock cycle.
2. Read CNTH. This will automatically cause the contents of TEMP to be read instead
of the current value of CNTH.
The result is a snapshot of the 16-bit CNT[H:L] value at the time CNTL was read.
Figure 4-1.
16- bit read access.
CNTH
CNTL
TEMP
Rn
CNTH
CNTL
TEMP
R(n+1)
Rn
R(n+1)
1
2
4.2 16-bit Write
Figure 4-2 illustrates how to perform a 16-bit and what happens internally:
1. Write CNTL. This will cause the TEMP register to be updated with the new value
for CNTL.
2. Write CNTH. This will cause CNTL to be updated with the contents of the TEMP
register at the same time as CNTH is updated.
The result is that the 16-bit CNT[H:L] value is updated in the same clock cycle.
8045A-AVR-02/08
