Rainbow Electronics ATAR862-3 - Manual (Page 80)

80
ATAR862-3
4556B–4BMCU–02/03
Combination Mode 5:
Biphase Modulation 2 SSI mode 1: 8-bit shift register internal data output (SO) to the Timer 2
modulator stage
Timer 2 mode 3: 8-bit compare counter and 4-bit prescaler
Timer 2 output mode 4: The modulator 2 of Timer 2 modulates the SSI data output
to Biphase code
The 4-bit stage can be used as prescaler for the SSI to generate the stop signal for mod-
ulator 2. The SSI has a special mode to supply the prescaler via the shift clock. The
control output signal (OMSK) of the SSI is used as stop signal for the modulator. Figure
72 shows an example for a 13-bit Biphase telegram.
Figure 80. Biphase Modulation
0 0 0 0 0 0 0 0 1 2 3 4 5 0
Counter 2/1 = Compare Register 2/1 (= 5)
Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
SCLI
Buffer full
SIR
SO
SC
MSM
Timer 2
Mode 3
SCL
Counter 2/1
OMSK
T2O
0 1 2