atam894 ATMEL Corporation, atam894 Datasheet - Page 52

• Manufacturer Part Number: atam894
• Description: Atam894 8k-flash Microcontroller
• Manufacturer: ATMEL Corporation

52
ATAM894
Timer 3 – Mode 8: FSK Modulation with Shift Register Data (SO)
The two compare registers are used for generating two different time intervals. The SSI internal
data output (SO) selects which compare register is used for the output frequency generation. A
'0' level at the SSI data output enables the compare register 1. A '1' level enables compare reg-
ister 2. The compare- and compare mode registers must be programmed to generate the two
frequencies via the output toggle flip-flop. The SSI can be supplied with the toggle signal of
Timer 2. The Timer 3 counter is driven by an internal or external clock source. The Timer 2
counter is driven by the Counter 3 (TOG3) (see section “Combination Mode 13”).
Figure 6-31. FSK Modulation
Timer 3 – Mode 9: Pulse-width Modulation with the Shift Register
The two compare registers are used for generating two different time intervals. The SSI internal
data output (SO) selects which compare register is used for the output pulse generation. In this
mode both compare- and compare mode registers must be programmed for generating the two
pulse widths. It is also useful to enable the single-action mode for extreme duty-cycles. Timer 2
is used as baud-rate generator and for the trigger restart of Timer 3. The SSI must be supplied
with a toggle signal of Timer 2. The counter is driven by an internal or external clock source (see
section “Combination Mode 7”).
Figure 6-32. Pulse-width Modulation
Counter 3
Counter 3
CM31
CM32
TOG2
CM31
CM32
T3R
T3O
SCO
SO
T3O
T3R
SIR
SO
0 0 0 0 0 0 0 0 0
0 1 2 3 4 0 1 2 3 4 0 1 2 3
0
0
0 0 0 0
0
0 0 0 0 0 1 2 3 4 5 6 7 8 9101112 131415 0 1 2 3 4 5
4 0 1 2 0 1 2 0 1 2 0 1 2 0 1 2 0 1 2 0 1 2 0 1 2 3
1
1
6 7 8
0
9
10
1112
13
4679D–4BMCU–05/05
14
15
0
0
4 0
1
2 3
1
1
4