MT90870AG Zarlink, MT90870AG Datasheet - Page 23

• Manufacturer Part Number: MT90870AG
• Description: Switch Fabric 12K x 12K/8K x 4K 1.8V/3.3V 272-Pin BGA Tray
• Manufacturer: Zarlink

Specifications of MT90870AG

• Package: 272BGA
• Number Of Ports: 32
• Fabric Size: 12K x 12K|8K x 4K
• Switch Core: Non-Blocking|Blocking
• Port Speed: 2.048|4.096|8.192|16.384 Mbps
• Operating Supply Voltage: 1.8|3.3 V

2.3
The Backplane frame pulse (FP8i) is an 8 kHz input signal active for 122 ns or 244 ns at the frame boundary. The
FPW bit in the Control Register must be set according to the applied pulse width. See Pin Description and Table
16, Control Register Bits, for details.
The active state and timing of FP8i may conform either to the ST-BUS or to the GCI-BUS as shown in Figure 6,
Local Port Timing Diagram for 2,4,8 and 16 Mb/s stream rates, and Figure 7, Backplane Port Timing Diagram for 2,
4, 8, 16 and 32 Mb/s stream rates. The MT90869 will automatically detect whether an ST-BUS or a GCI-BUS style
frame pulse is being used for the master frame pulse (FP8i). The device will detect the frame boundary alignment
using the rising edge of the input clock (C8i), provided the C8IPOL bit in Table 16, “Control Register Bits,” on
page 52 is set to one. Before the C8IPOL bit is set to one, the frame boundary will not be detected correctly. For the
BSTi/BSTo0-15
BSTi/BSTo0-15
BSTi/BSTo0-31
BSTi/BSTo0-31
BSTi/BSTo0-31
BSTi/BSTo0-31
BSTi/BSTo0-31
BSTi/BSTo0-31
BSTi/BSTo0-31
BSTi/BSTo0-31
FP8i (ST-BUS)
(8.192 MHz)
(32 Mb/s) GCI
(16 Mb/s) GCI
(32 Mb/s) ST
(16 Mb/s) ST
(4 Mb/s) GCI
C8i (ST-BUS)
(8 Mb/s) GCI
(2 Mb/s) GCI
(8.192 MHz)
(8 Mb/s) ST
(4 Mb/s) ST
(2 Mb/s) ST
Backplane Frame Pulse Input and Master Input Clock Timing
C8i (GCI)
FP8i (GCI)
(8 kHz)
(8 kHz)
Figure 7 - Backplane Port Timing Diagram for 2, 4, 8, 16 and 32 Mb/s stream rates
0
7
0
7
3
4
1
6
2
5
0
7
1 0
6 7
0
7
7
0
7
0
6
1
7
0
Channel 0
5
Channel 0
2
6
1
4
3
7
0
3
4
5
2
2
5
6
1
Channel 0
Channel 0
Channel 0
Channel 0
Channel 0
Channel 0
Channel 0
Channel 0
1 0
6 7
4
3
7
0
7
0
3
4
Zarlink Semiconductor Inc.
6
1
5
2
5
2
Channel 1
Channel 1
2
5
MT90870
4
3
6
1
3
4
1
6
2
5
23
4
3
1 0
6 7
0
7
6
1
3
4
5
2
Channel 510
Channel 510
6
1
4
3
1
6
3
4
5
2
2
5
Channel 127
Channel 127
Channel 255
Channel 255
2
5
Channel 63
Channel 63
Channel 31
Channel 31
1 0
6 7
4
3
0
7
7
0
3
4
6
1
1
6
Channel 511
5
Channel 511
2
2
5
4
3
0
7
3
4
1
6
2
5
0
7
1 0
6 7
0
7
Data Sheet
7 6
0 1
7
0
7
0
7
0
7
0