MT90870 Zarlink Semiconductor, Inc., MT90870 Datasheet - Page 21

• Manufacturer Part Number: MT90870
• Description: Flexible 12k Digital Switch (F12kDX)
• Manufacturer: Zarlink Semiconductor, Inc.

Preliminary Information
Figure 12, Local Port External High Impedance Control Bit Timing (ST-Bus mode) shows the channel control
bits for LCSTo0 and LCSTo1 in one possible scenario which includes stream LSTo0 at a data-rate of
16.384Mb/s, LSTo1 at 8.192Mb/s, LSTo6 at 4.096Mb/s and LSTo7 at 2.048Mb/s. All remaining streams are
operated at a data-rate of 16.384Mb/s.
4.1.2
The Local Output Enable Bit (LE) of the Local Connection Memory has direcect per-channel control on the
high-impedance state of the Local Output streams, LSTo0-15. Programming the LE bit to a LOW state will set
the stream output of the MT90870 to High Impedance for the duration of the channel period. See Section 12.3,
Local Connection Memory Bit Definition, for programming details.
The LCSTo0-1 outputs remain active.
Period
C16o
2039
2040
2041
2042
2043
2044
2045
2046
2047
2048
2029
2030
2031
2032
2033
2034
2035
2036
2037
2038
2039
2040
etc
etc
10
12
13
14
15
16
17
11
1
2
3
4
5
6
7
8
9
1
LORS Set HIGH
Table 2 - LCSTo Allocation of Channel Control Bits to the Output Streams
LCSTo0
14
0
2
2
4
2
4
2
etc
etc
etc
10
12
10
12
14
10
12
14
14
10
12
14
Allocated Stream No.
3-3
4
6
8
0
4
6
8
0
6
8
0
0
2
4
6
8
0
2
3-1
3-3
3-3
3-4
3-3
3-4
3-2
LCSTo1
15
etc
etc
etc
11
13
11
13
15
11
13
15
15
11
13
15
1
3
5
7
9
1
3
5
7
9
1
3
5
7
9
1
3
5
1
3
5
7
9
1
3
3-2
16Mb/s
Ch 254
Ch 254
Ch 255
Ch 255
Ch 255
Ch 255
Ch 255
Ch 255
Ch 255
Ch 255
Ch 0
Ch 0
Ch 0
Ch 0
Ch 0
Ch 0
Ch 0
Ch 0
Ch 1
Ch 1
Ch 1
Ch 1
Ch 1
Ch 1
Ch 1
Ch 1
Ch 2
Ch 2
Ch 2
Ch 2
Ch 2
Ch 2
Ch 2
Ch 2
Ch 3
Ch 3
Ch 3
Ch 0
Ch 0
etc
etc
Allocated Channel No.
Ch 127
Ch 127
Ch 127
Ch 127
Ch 127
Ch 127
Ch 127
Ch 127
Ch 127
Ch 127
8Mb/s
Ch 0
Ch 0
Ch 0
Ch 0
Ch 0
Ch 0
Ch 0
Ch 0
Ch 0
Ch 0
Ch 0
Ch 0
Ch 0
Ch 0
Ch 0
Ch 0
Ch 1
Ch 1
Ch 1
Ch 1
Ch 1
Ch 1
Ch 1
Ch 1
Ch 1
Ch 1
Ch 1
Ch 0
Ch 0
etc
etc
4Mb/s
Ch 63
Ch 63
Ch 63
Ch 63
Ch 63
Ch 63
Ch 63
Ch 63
Ch 63
Ch 63
Ch 0
Ch 0
Ch 0
Ch 0
Ch 0
Ch 0
Ch 0
Ch 0
Ch 0
Ch 0
Ch 0
Ch 0
Ch 0
Ch 0
Ch 0
Ch 0
Ch 0
Ch 0
Ch 0
Ch 0
Ch 0
Ch 0
Ch 0
Ch 0
Ch 0
Ch 0
Ch 0
Ch 0
Ch 0
etc
etc
2
2Mb/s
Ch 31
Ch 31
Ch 31
Ch 31
Ch 31
Ch 31
Ch 31
Ch 31
Ch 31
Ch 31
Ch 0
Ch 0
Ch 0
Ch 0
Ch 0
Ch 0
Ch 0
Ch 0
Ch 0
Ch 0
Ch 0
Ch 0
Ch 0
Ch 0
Ch 0
Ch 0
Ch 0
Ch 0
Ch 0
Ch 0
Ch 0
Ch 0
Ch 0
Ch 0
Ch 0
Ch 0
Ch 0
Ch 0
Ch 0
etc
etc
MT90870
Boundary
Frame
21