ZL50022
Data Sheet
FPi (61 ns)
FPINP = 0
FPINPOS = 0
FPi (61 ns)
FPINP = 1
FPINPOS = 0
FPi (61 ns)
FPINP = 0
FPINPOS = 1
FPi (61 ns)
FPINP = 1
FPINPOS = 1
CKi
(16.384 MHz)
CKINP = 0
CKi
(16.384 MHz)
CKINP = 1
Channel N = 127
Channel 0
STi
1
4 3 2 1
5
3
5
2 1 0 7 6
0 7 6 5
4
(8.192 Mbps)
Channel 0
Channel N = 255
STi
321076543210765432
321076543210765432
(16.384 Mbps)
Figure 6 - Input Timing when CKIN1 - 0 = “00” in the CR
5.0 ST-BUS and GCI-Bus Timing
The ZL50022 is capable of operating using either the ST-BUS or GCI-Bus standards. The output timing that the
device generates is defined by the bus standard. In the ST-BUS standard, the output frame boundary is defined by
the falling edge of CKo while FPo is low. In the GCI-Bus standard, the frame boundary is defined by the rising edge
of CKo while FPo goes high. The data rates define the number of channels that are available in a 125 µs frame
pulse period.
By default, the ZL50022 is configured for ST-BUS input and output timing. To set the input timing to conform to the
GCI-Bus standard, FPINPOS (bit 9) and FPINP (bit 7) in the Control Register (CR) must be set. To set output timing
to conform to the GCI-Bus standard, FPO[n]P and FPO[n]POS must be set in the Output Clock and Frame Pulse
Selection Register (OCFSR). The CKO[n]P bits in the Output Clock and Frame Pulse Selection Register control the
polarity (positive-going or negative-going) of the output clocks.
6.0 Output Timing Generation
The ZL50022 generates frame pulse and clock timing. There are five output frame pulse pins (FPo0 - 3, 5) and six
output clock pins (CKo0 - 5). All output frame pulses are 8 kHz output signals. By default, the output frame
boundary is defined by the falling edge of the CKo0, while FPo0 is low. At the output frame boundary, the CKo1,
CKo2 and CKo3 output clocks will by default have a falling edge, while FPo1, FPo2 and FPo3 will be low. At the
output frame boundary, CKo4 will by default have a falling edge while FPo0 is low (CKo4 has no corresponding
output frame pulse). At the output frame boundary, CKo5 will by default have a rising edge while FPo5 (FPo_OFF2)
will be low. The duration of the frame pulse low cycle and the frequency of the corresponding output clock are
shown in Table 3 on page 25. Every frame pulse and clock output can be tristated by programming the enable bits
in the Internal Mode Selection (IMS) register.
24
Zarlink Semiconductor Inc.
ZARLINK [ ZARLINK SEMICONDUCTOR INC ]
