MT8986 Mitel Semiconductor, MT8986 Datasheet - Page 19

• Manufacturer Part Number: MT8986
• Description: CMOS ST-BUS FAMILY Multiple Rate Digital Switch
• Manufacturer: Mitel Semiconductor

x=Don’t care
x=Don’t care
These bits are only used when the Switching Configuration bits enable stream pair selection capability (SCB 1-0 =10) and the Input Data Rate
Selection bits enable 2 Mb/s operation (IDR-0 = 00). In all other modes, the contents of this register are ignored.
If frame input offset operation is not required, this register should be cleared by the CPU during system initialization.
Stream Pair Selection Register - Read/Write (ONLY PROVIDED IN THE 44 PIN PACKAGES)
BIT
BIT
5-3
2-0
7-5
OFB2-0
SPA2-0
SPB2-0
NAME
NAME
Stream Pair A selection. These three bits define which pair of streams are going to be
connected to the switch matrix, together with the permanently connected streams
STi0-1 / STo0-1.
Stream Pair B selection. These three bits define which pair of streams are going to be
connected to the switch matrix, together with the permanently connected streams
STi0-1 / STo0-1.
Offset Bits 2-0. These three bits define the time it takes the Serial Interface receiver to
recognize and store the first bit of the serial input streams; i.e., to start assuming a new
internal frame. The input frame offset can be selected to be up to 4 CK clock periods from
the time when frame pulse input signal is applied to the FR input.
OFB2
Figure 7 - Stream Pair Selection (SPS) Register
7
X
7
Frame Input Offset Register - Read/Write
Figure 8 - Frame Input Offset (FIO) Register
SPA2
OFB2
SPB2
OFB1
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
6
X
6
OFB0
SPA2
5
5
SPA1
SPB1
OFB1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
SPA1
4
4
X
SPA0
SPA0
SPB0
OFB0
X
3
3
DESCRIPTION
DESCRIPTION
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
SPB2
2
X
2
Stream Pair A Connected
Stream Pair B Connected
Number of Clock Periods
Normal Operation. No bit offsetting.
Reserved
Reserved
Reserved
SPB1
1
1
X
STi2 / STo2
STi3 / STo3
STi4 / STo4
STi5 / STo5
STi6 / STo6
STi7 / STo7
STi8 / STo8
STi9 / STo9
STi2 / STo2
STi3 / STo3
STi4 / STo4
STi5 / STo5
STi6 / STo6
STi7 / STo7
STi8 / STo8
STi9 / STo9
1
2
3
4
SPB0
X
0
0
MT8986
2-81