Rainbow Electronics ATAR862-3 - Manual (Page 49)

49
ATAR862-3
4556B–4BMCU–02/03
Timer 2 Output Mode 4 Biphase Modulator: Timer 2 Modulates the SSI Internal Data Output (SO) to Biphase
Code.
Figure 47. Biphase Modulation
Timer 2 Output Mode 5 Manchester Modulator: Timer 2 Modulates the SSI internal data output (SO) to
Manchester code
Figure 48. Manchester Modulation
Timer 2 Output Mode 7 In this mode the timer overflow defines the period and the compare register defines the
duty cycle. During one period only the first compare match occurrence is used to toggle
the timer output flip-flop, until the overflow all further compare match are ignored. This
avoids the situation that changing the compare register causes the occurrence of sev-
eral compare match during one period. The resolution at the pulse-width modulation
Timer 2 mode 1 is 12-bit and all other Timer 2 modes are 8-bit.
PWM Mode: Pulse-width modulation output on Timer 2 output pin (T2O)
Figure 49. PWM Modulation
TOG2
SC
SO
T2O
0 0 0 0
0 0 1 1 0 1 0 1
1 1 1 1
8-bit SR-Data
Bit 7 Bit 0
Data: 00110101
TOG2
SC
SO
T2O
0 0 0
0 0 1 1 0 1 0 1
1 1 1 1
8-bit SR-Data
Bit 7 Bit 0
0
Bit 7 Bit 0
Data: 00110101
0 0 50 255 100 0 255 0 150 255 0 50 255 0 100
T2R
Input clock
Counter 2/2
Counter 2/2
OVF2
CM2
INT4
T2O
load the next
compare value T2CO2=150 load load
T1 T2 T3 T1 T2
T T T T T