MT8986 Mitel Semiconductor, MT8986 Datasheet - Page 17

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

x=Don’t care
BIT
4-3
6
5
2
1
0
CAB6-5
NAME
SAB3
CSTo
V/C
MC
OE
Variable/Constant Throughput Delay Mode. This bit is used to select between Variable
(LOW) and Constant Delay (HIGH) modes in a per-channel basis. Tables 1 and 2
describe the switching configurations that have this function. In the modes where this
function is not available, this bit has not effect.
Source Stream Address bit 3. This bit is used along with bits SAB0-2 in CML to select
up to 16 different source streams for the connection. Depending on the state of DMO bit
and the switching configuration enabled, not all SAB3-0 bits have to be used.
See Tables 9 and 10 for details on the utilization of the SAB bits.
Source Channel Address bits 5 and 6. These two bits are used together with bits
CAB0-4 in Connect Memory Low to select up 128 different source channels for the
connection. Depending on the data rate used in the input/output streams, 5, 6 or all 7
CAB bits can be used respectively, to select 32, 64 or 128 different channels.
Message Channel. When 1, the contents of the corresponding location in Connection
Memory Low are output on the corresponding channel and stream. When 0, the contents
of the programmed location in Connection Memory Low act as an address for the Data
Memory and so determine the source of the connection to the location’s channel and
stream.
CSTo Bit. This bit is only available in 2.048 Mb/s applications. It drives a bit time on the
CSTo output pin.
Output Enable. This bit enables the output drivers on a per-channel basis. This allows
individual channels on individual streams to be made high-impedance, allowing switch
matrices to be constructed. A HIGH enables the driver and a LOW disables it.
See Tables 9 and 10 for details on the utilization of the CAB bits.
Figure 5 - Connection Memory High (CMH) Bits
X
7
Connection Memory High - Read/Write
V/C
6
SAB3
5
CAB6
(CM high bits)
4
CAB5
3
DESCRIPTION
MC
2
CSTo
1
OE
0
MT8986
2-79