MITEL MT8982AC

ISO-CMOS ST-BUS FAMILY MT8982
Small Digital Switch (MiniDX)

Features
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•
•
•
•
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•
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ISSUE 6
Ordering Information
MT8982AC
16 Pin Ceramic DIP
MT8982AE
16 Pin Plastic DIP
MT8982AS
16 Pin SOIC
MT8982AN
20 Pin SSOP
-40 to +85°C
ST-BUS/GCI compatible switch matrix
64 channel non-blocking time switch
2 x 32 channel serial inputs and outputs
Per-channel tristate control
4-pin serial microprocessor interface
Patented message mode
Low power consumption (10 mW)
Single 5 volt supply
Description
The MT8982 Small Digital Switch (MiniDX) is a nonblocking CMOS time switch with a capacity of up to
64 - 8 bit Time Division Multiplexed (TDM) encoded
voice or data channels. It is a size-optimized version
of MITEL's successful MT8980D Digital Switches,
providing switching capability in cost sensitive
applications such as telephone sets and digital key
systems. The TDM interface to the device is via two
pairs of 2048 kbit/s serial streams with 32 64 kbit/s
channels per stream (ST-BUS). A serial microport
provides access to the device for programming the
required connections.
The serial microport is
compatible with most common microcontrollers. The
unique message mode capability allows the MT8982
to act as a controller for other members of MITEL's
ST-BUS family of components.
Applications
•
•
•
•
•
•
Cost sensitive digital switching applications
Digital key telephone systems
GCI/ST-BUS conversion
ST-BUS device control interface
ISDN telephone set support circuit
Interprocessor communication
STi0
STi1
Serial
to
Parallel
Converter
64 x 8
Data Memory
F0i
C4i
F0o
May 1995
Output
Mux
Parallel
to
Serial
Converter
STo0
STo1
Address
Mux
Address
Counters
Data
Mux
RxD/CSTi0
TxD/NC
SCLK/CSTi1
Serial
Microport
64 x 9
Connect Memory
3-State
Control
CS/CMS
MPS
Address
Mux
ODE
Figure 1 - Functional Block Diagram
2-31
MT8982
ISO-CMOS
STi0
STi1
STo0
STo1
RxD/CSTi0
TxD/NC
SCLK/CSTi1
VSS
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
VDD
ODE
IC
MPS
F0o
F0i
C4i
CS
STi0
STi1
NC
STo0
STo1
RxD/CSTi0
TxD/NC
NC
SCLK/CSTi1
VSS
1
2
3
4
5
6
7
8
9
10
16 PIN CERDIP/PLASTIC/SOIC
20
19
18
17
16
15
14
13
12
11
VDD
ODE
IC
MPS
F0o
NC
F0i
NC
C4i
CS
20 PIN SSOP
Figure 2 - Pin Connections
Pin Description
Pin #
Name
Description
16
20
1-2
1-2
STi0STi1
Serial TDM Input 0 and 1 (Inputs). 2048 kbit/s input data streams containing 32 8-bit
channels synchronized to F0i.
3-4
4-5
STo0STo1
Serial TDM Output 0 and 1 (Outputs). 2048 kbit/s output data streams containing 32
8-bit channels synchronized to F0i.
5
6
RxD/
CSTi0
Received Data/Control Stream Input 0 (Input). When MPS is low, this pin receives serial
microport data clocked in by the rising edge SCLK. When MPS is high, this pin receives a
2048 kbit/s serial TDM stream containing 32 8-bit channels, which are written into the
Connect Memory locations corresponding to STo0.
6
7
TxD
Transmit Data (Output). When MPS is low, serial microport data is clocked out on this pin
by the falling edge of SCLK. When MPS is high this output is disabled.
7
9
SCLK/
CSTi1
Serial Microport Clock/Control Stream Input 1 (Input). When MPS is low, this pin
receives a clock which is used to clock data to/from a microcontroller via a serial microport.
When MPS is high, this pin receives a 2048 kbit/s serial TDM stream containing 32 8-bit
channels, which are written into the Connect Memory locations corresponding to STo1.
8
10
VSS
Power Input. Negative supply (ground).
9
11
CS
Chip Select (Input). When MPS is low, a low on this pin enables the serial microport. A
high on this pin disables RxD and tristates TxD. When MPS is high, this pin must be low.
10
12
C4i
Serial TDM Clock (Input). This clock input is used to clock the TDM data into and out of
the device and refreshes the internal dynamic RAM. The clock rate is 4.096 MHz and data
is clocked in on the rising edge of C4i three-quarters of the way through a bit period.
11
14
F0i
Frame Pulse (Input). This input is the frame synchronization pulse for the 2048 kbit/s
serial TDM streams. It may be either active low stradling the frame boundary (ST-BUS) or
active high at the beginning of timeslot 5 (GCI).
12
16
F0o
Frame Pulse (Output). This pin outputs a frame pulse in the opposite format to F0i (GCI
or ST-BUS) delayed or advanced by five channels.
13
17
MPS
Microport Select (Input). When this pin is held low, the serial microport is in normal mode.
When this pin is high, the microport is in serial bus mode.
14
18
IC
15
19
ODE
Output Drive Enable (Input). When this pin is held high, the STo0 and STo1 output drivers
function normally. When this pin is low, STo0 and STo1 are tristated.
NB: When ODE is high, individual channels on STo0 and STo1 can be tristated under
software control.
16
20
VDD
Power Input. Positive supply.
3,8,
13,15
NC
No Connection.
2-32
Internal Connection. Tie to VSS for normal operation.
ISO-CMOS
Functional Description
The MT8982 (MiniDX) provides cost effective time
switching capability for small size applications
utilizing up to two serial Time Division Multiplexed
(TDM) streams. Each TDM stream consists of 32 64
kb/s channels, giving the MiniDX a maximum
capacity of 64 channels. The input framing signal
may be either a ST-BUS or a GCI frame pulse. The
MT8982 will output a delayed or advanced frame
pulse in the opposite format to permit conversion
between the two formats.
The MiniDX can switch data from any channel in one
of the two serial input TDM streams to any channel in
either of the two serial output TDM streams. The
microcontroller controlling the MiniDX writes to the
MT8982 Connect Memory to establish the
connection between the required input TDM channel
and the selected output TDM channel(s). By reading
the Connect Memory the microcontroller can check
switched connections which have already been
established.
The MiniDX can also operate in message mode
where the microcontroller transmits the data on the
TDM serial stream. The microcontroller writes to the
MT8982 Connect Memory to transmit data on the
required output TDM channels. Reading the Data
Memory of the MT8982 allows the microcontroller to
receive messages from TDM input channels. These
operations are useful for control of other ST-BUS
components or for interprocessor communication.
Hardware Description
TDM Interface
The MT8982 continuously receives TDM serial data
at 2048 kbit/s through two serial inputs. These serial
streams are then converted into a parallel format and
stored sequentially in a 64x8 bit Data Memory. The
sequential addressing is generated by an internal
counter that is reset by the input 8 kHz frame pulse
(F0i) which marks the frame boundaries of the
incoming serial data stream. This counter increments
with each timeslot so that it matches the binary count
of the timeslot of the incoming data. The TDM
timeslot count always corresponds to the ST-BUS
channel positions. An extra address bit is used to
differentiate between the two input data streams.
MT8982
formatted frame pulse is active high at the beginning
of timeslot 5 (relative to the MT8982) and idles low.
The MT8982 automatically determines the type of
frame pulse from the level of the idle over five clock
periods. A ST-BUS formatted frame pulse resets the
internal address counters to zero. A GCI formatted
frame pulse resets the counters to five.
F0o outputs a frame pulse in the opposite format. If
F0i is a ST-BUS formatted frame pulse, F0o will be a
GCI formatted frame pulse delayed by five channels
after F0i. If F0i is a GCI formatted frame pulse, F0o
will be a ST-BUS formatted frame pulse delayed by
27 channels (32-5).
During normal operation every second falling edge of
the clock marks a timeslot boundary and the input
data is clocked in by the rising edge, three-quarters
of the way into the bit cell. The master clock must
be 4.096 MHz for the F0o signal to be valid and to
receive a GCI formatted F0i.
Data which is output onto a TDM serial output
channel may come from two sources; the Data
Memory or the Connect Memory. If a channel is
configured in connection mode, the source of output
data is the Data Memory. If a channel is configured
in message mode, the source of the output data is
the Connect Memory. Data destined for a particular
channel on the serial output links is read from the
data or connect memory in the previous channel
timeslot. This allows for delay in RAM access and
parallel-to-serial conversion.
Each output data
channel can also be placed in tristate mode.
When an output channel is in connection mode, the
TDM output data is read from a Data Memory
location pointed to by an address stored in the 64x8
bit Connect Memory.
The Connect Memory
locations are addressed sequentially, with each
location corresponding to an output TDM link/
channel. In the channel time before the data is to be
output, the contents of each Connect Memory
location are output to the address bus of the Data
Memory. The contents of the Data Memory at the
selected address are then transferred to the parallelto-serial converter. The parallel-to-serial converter
outputs onto the TDM serial stream during the
correct channel time. By having the output channel
specify the input channel, the user can route the
same input channel to several output channels. This
function is useful for broadcasting or resource
channel uses.
The input 8 kHz frame pulse may be either ST-BUS
or GCI formatted. A ST-BUS formatted frame pulse
is an active low signal which straddles the frame
boundary. It idles high the rest of the time. A GCI
2-33
MT8982
ISO-CMOS
When an output channel is in message mode, the
data for the output channel originates from the
microcontroller. The microcontroller writes data to
the Connect Memory location which corresponds to
the output link and channel number. The contents of
the Connect Memory are transferred directly to the
serial-to-parallel converter one channel time before it
is to be output. The Connect Memory data is output
MSB first, repetitively once per frame, until it is
changed by the microcontroller.
If the output channel is configured in tristate mode,
the TDM serial stream output will be placed in high
impedance during that channel time. This mode is
entered by configuring the channel into connection
mode and then setting the tristate control bit. All
channels on both output TDM streams can be
tristated by pulling pin 16 (ODE) low. This overrides
the individual channel programming.
The Data and Connect Memories are dynamic
memories. They are refreshed by the sequential
addressing generated by C4i.
Microcontroller Interface
The MT8982 is controlled via a synchronous, serial
microport. The microport is compatible with Intel's
MCS-51 serial port Mode 0 specifications, Motorola's
Serial Peripheral Interface (SPI) specifications, and
National's MicroWire specifications.
The port
consists of a transmit data line (TxD), a receive data
line (RxD), a chip select line (CS), and a
synchronous clock input (SCLK).
All memory
locations and control functions on the MiniDX are
accessed through this port. The microport may also
be configured in serial bus mode where data is
clocked into the Connect Memory in the same way
as STi0 and STi1 are clocked into Data Memory.
In serial microport mode, CS must be low to enable a
microport access. SCLK clocks the serial microport
data in or out through RxD and TxD, LSB first. The
TxD output driver is tristated when it is inactive. This
allows RxD and TxD to be connected together for a
single TxD/RxD line as used in the INTEL MCS-51
microcontrollers. Figure 3 shows a serial microport
access cycle.
A microport access cycle (microcycle) begins with a
falling edge on CS. Eight bits of data are clocked
into RxD by the rising edge of SCLK. Two of these
eight bits indicate whether the microcycle operation
is a read or a write, the rest of the bits are used for
addressing. These eight bits are defined as the
command/ address byte (Table 1). If the microcyle
operation is a write, another eight bits are clocked
➀
COMMAND/ADDRESS
RxD
D0 D1 D2 D3 D4 D5 D6 D7
DATA INPUT/OUTPUT
➀
D0 D1 D2 D3 D4 D5 D6 D7
D0 D1 D2 D3 D4 D5 D6 D7
D0 D1 D2 D3 D4 D5 D6 D7
TxD
➃ COMMAND/ADDRESS
D0 D1 D2 D3 D4 D5 D6 D7
SCLK ➁
CS
➃
➂
➀ Minimum delay between accesses equals 3.0 µsec.
➁ The Mini Dx: - latches received data in on the rising edge of SCLK
- outputs transmit data on the falling edge of SCLK
➂ The falling edge of CS indicates that a COMMAND/ADDRESS byte will be transmitted. Subsequent byte is always data.
➃ Subsequent write microcycles may flow without raising CS. CS must go high after a read microcycle.
Figure 3 - Serial Microport Timing
2-34
ISO-CMOS
into RxD by the rising edges of the next eight SCLK
cycles. If the operation is a read, eight data bits are
clocked from TxD by the falling edges of the next
eight SCLK cycles. The rising edge of CS tristates
TxD after the last transmitted bit.
Successive write microcycles can take place while
CS remains low, with each microcycle following the
sequence of a command/address byte followed by a
data byte. CS must go high after a read microcycle.
Note that a command/address byte must always
follow the high to low transition on CS.
When the MPS input is pulled high and the CS input
is pulled low, the microport is put into serial bus
mode. Pins RxD and SCLK become CSTi0 and
CSTi1, respectively, and are configured as 2048 kbit/
s serial streams with 32 channels each. The frame
and timeslot boundaries are determined by F0i and
C4. Each channel on CSTi0 and CSTi1 is stored in
the connect memory address corresponding to the
link and channel number. The Data Memory and the
Connect Memory cannot be read when the microport
is in serial bus mode.
MT8982
Device Timing
During each TDM timeslot, eight read or write
operations occur internally in the MT8982. These are
shown in Figure 4. During the first two bit periods,
data received in the previous timeslot on the two
input TDM streams is loaded into the Data Memory.
Bit periods 2 and 6 are serial microport access
windows; data may be read from, or written to any
accessible memory location. During bit periods 3
and 5, data is read from the connect memory for the
next timeslot on links 0 and 1 respectively. The Data
Memory locations which are addressed by the
previous reads of the connect memory are accessed
during bit periods 4 and 7.
When the microport is in serial bus mode, bit periods
2 and 6 have a slightly different function. Data from
the previous timeslot of CSTi0 and CSTi1
respectively is written to the corresponding connect
memory locations.
The transfer of information from the input TDM
streams to the output TDM streams results in a delay
through the MT8982. This delay is dependent only
on the combination of source and destination
Bit
Name
Description
7
Stream
Stream. This is the most significant bit of the address for the memory location that
is to be accessed. It corresponds to one of the TDM serial streams (0-1).
2-6
Ch0-Ch4
Channel 0-4. These bits are the five least significant bits of the address for the
memory location that is to be accessed. The binary value of these bits correspond
to a TDM channel (0-31).
0-1
Cmd0-Cmd1
Command Select 0-1. These two bits define the four command operations for the
MT8982. The destination addressed by the command is defined in bits 2-7 of the
Command/Address byte.
Cmd0-Cmd1
0-0
0-1
1-0
1-1
Read from Connect Memory.
Write to Connect Memory and set connection mode.
Read Data Memory.
Write to Connect Memory and set message mode.
Table 1. Command Address Byte
Bit
Name
Description
7
NA
6
ODE
Output Drive Enable. When this bit is set, the addressed TDM channel is placed
in tristate. When low, the output is enabled.
5
STi
Input Stream. This bit defines the input TDM stream from which the output data is
sourced (0-1).
0-4
SC0-SC4
Unused.
Source Channel 0-4. The binary value of these bits defines the input channel from
which the output data is sourced (0-31).
Table 2. Connect Memory Connection Mode Data Byte
2-35
MT8982
ISO-CMOS
Channel 31
Channel 0
F0i
C4
Bit 0
Microport
Mode
Wr DM
Link 0
Ch 31
Bit 1
Wr DM
Link 1
Ch 31
Bit 2
µP
Bit 3
Bit 4
Bit 5
Rd CM
Link 0
Ch 1
Rd DM
Link 0
Ch 1
Rd CM
Link 1
Ch 1
Wr CM
Link 0
Ch 31
Serial Port Mode
Bit 6
µP
Bit 7
Rd DM
Link 1
Ch 1
Wr CM
Link 1
Ch 31
Figure 4 - Internal Memory Access Windows
channels and is not dependent on the input and
output streams. The delays are given in Table 3.
The maximum delay is one frame plus one channel;
the minimum delay is two channels.
Input
Channel
Output
Channel
Delay
n
m = n, n+1
m- n + 32 channels
n
m > n+1
m- n channels
n
m<n
32- (n-m) channels
Table 3. Input Channel to Output Channel Delay
Times
The following delays apply to writing data to the
Connect Memory in message mode. For stream 0,
data must be written to a Connect Memory location
at least one timeslot before the corresponding output
channel or the output data will be delayed by one
frame. For stream 1, data must be written at least
two timeslots before the output channel or the output
data will be delayed by one frame.
Device Programming
Microport Mode
In serial microport mode, the MT8982 is
programmed and read using microcycles which
consist of a command/address byte followed by a
data byte.
The Command/Address Byte is shown in Table 1.
Bits 0 and 1 are the command bits (Cmd0-1), and
are used to indicate the type of microcycle access.
The microcontroller can read the Data Memory, read
or write the Connect Memory, and set per-channel
message or connection mode. Bits 2 to 6 of the
command/address byte (Ch0-Ch4) correlate to a
channel on a TDM stream (0-31). Bit 7 (STREAM)
correlates to stream 0 or stream 1. These bits
address the corresponding Data Memory or Connect
Memory location.
The microcycle operations selected
command/address byte are as follows:
by
the
Read Connect Memory (Cmd0-1: 0,0)
Bits 0 to 7 of the addressed Connect Memory
location will be transmitted to the microcontroller
in the following data byte. Depending on what
the last Connect Memory write mode was, the
data transmitted could be a message byte or a
Connection Mode data byte.
2-36
ISO-CMOS
Write Connect Memory - Set Connection Mode
(Cmd0-1: 0,1)
The corresponding output channel to the
addressed Connect Memory location is
configured in connection mode. The Connection
Mode Data Byte (Table 2) will be received by the
MT8982 in the following data byte. Bits 0 to 4
(SC0-SC4) select the source input channel for
switching to this output channel. Bit 5 (STi)
selects the input stream. Bit 6 (ODE) enables/
disables tristate for this channel. Bit 7 is unused
in connection mode.
The connection is now complete.
The
microcontroller may now check that the connection is
correct:
•
•
Read Data Memory (Cmd0-1: 1,0)
The contents of the addressed Data Memory
location are transmitted to the microcontroller in
the following data byte.
Write Connect Memory - Set Message Mode
(Cmd0-1: 1,1)
The corresponding output channel to the
addressed Connect Memory location is
configured in message mode. The following data
byte will be received by the MT8982 and written
to the address Connect Memory location. The
data byte will be output directly to the
corresponding output channel.
The following example shows a typical programming
sequence for the MT8982. A connection is to be
made from stream 1 channel 6 to stream 0 channel
15:
•
•
•
The microcontroller pulls CS low.
The microcontroller transmits eight clock pulses
to SCLK and a Command/Address byte, HEX
3E, to RxD.
The Command/Address byte
addresses output channel 15, stream 0,
configures that channel as connection mode
and identifies the microcycle as a write to the
Connect Memory.
The microcontroller transmits another eight
clock pulses to SCLK and sends the
Connection Mode Data Byte, HEX 26, to RxD.
The Connection Mode Data Byte addresses
input channel 6, stream 1 in the Data Memory.
Note that at least two microseconds must occur
between the two accesses.
MT8982
•
The microcontroller transmits eight clock pulses
to SCLK and a Command/Address byte, HEX
3C, to RxD.
The Command/Address byte
addresses output channel 15, stream 0 and
identifies the microcycle as a read from the
Connect Memory.
The microcontroller transmits another eight
clock pulses to SCLK. The MT8982 outputs the
Connect Memory data, HEX 26, on TxD. At
least two microseconds must occur between
the two accesses to ensure that the MiniDX can
clock out the data.
CS goes high to terminate the session.
This connection is only in one direction. To make a
bidirectional connection the MT8982 must also be
programmed to connect stream 0 channel 15 to
stream 1 channel 6.
Serial Bus Mode
When the microport is in serial bus mode the
MT8982 is programmed via the two ST-BUS serial
streams CSTi0 and CSTi1. Each channel in these
two streams is written directly into the corresponding
address in the Connect Memory. The data written to
the Connect Memory is always the Connection Mode
Data Byte as described in Table 2. To set up a
connection, the Connection Mode Data Byte is
transmitted to the MT8982 on the CSTi stream and
channel number which is the same as the desired
STo stream and channel number. As long as the
device remains in serial bus mode, the Connection
Mode Data byte must be transmitted continuously,
every frame, to maintain the connection.
Message mode is not available when the device is in
serial bus mode. Also, neither the Connect Memory
nor the Data Memory can be read while the device is
in serial bus mode. MITEL’s MT8980, MT9080 and
MT8920 devices can all be used as programmable
parallel-to-ST-BUS serial interfaces for CSTi0 and
CSTi1.
Initialization
On power up the contents of the Connect Memory
can be in any state. In order to prevent false
programming of peripheral ST-BUS devices or false
data transmission, ODE should be kept low during
power up. This will keep the two TDM outputs in high
impedance until the MT8982 Connect Memory is
programmed.
2-37
MT8982
ISO-CMOS
Applications
ST-BUS to GCI Conversion
Digital Key Telephone System
The MT8982 MiniDX may be used to provide a
gateway between MITEL's ST-BUS family of
components and an architecture which utilizes the
General Circuit Interface (GCI) operating at 2048
kbit/s (Figure 8). The MT8982 performs automatic
adaptation of the different frame pulse signals. The
master frame pulse to the MT8982 can be supplied
either by the ST-BUS or the GCI components. The
MT8982 will then provide either a delayed or
advanced frame pulse to the other components as
shown in Figures 9 and 10.
Figure 5 shows a block diagram of a Digital Key
Telephone System (DKTS) implemented with the
MT8982.
This DKTS can support up to 64
connections organized in any combination of
subscriber lines or trunks. A very small system
consisting of six lines and one trunk can very easily
and economically be designed on one board. The
MT8982 significantly reduces the tracking and board
space required for competitive switch matrices.
Distributed Switching System
The MT8982 can be used to distribute switching
capability in a very large system. In Figure 6 the
MT8982 is shown with the microport in serial bus
mode. This allows the central microprocessor to set
up and tear down connections at the remote
locations by programming the remote MT8982's
through their CSTi pins. A microcontroller in each
remote switch would not be required.
When an ST-BUS component is supplying the master
frame pulse (F0i), the MiniDX will supply the output
frame pulse (F0o) delayed by five channels. This
ensures that frame integrity is maintained between
the ST-BUS and GCI components. When a GCI
component supplies the master frame pulse (F0i),
F0o is advanced by five channels.
Primary Rate Serial Controller
Figure 8 shows a block diagram of a GCI to ST-BUS
conversion circuit. External inversion of the clock
signal is required between the ST-BUS and GCI
components because the ST-BUS and GCI master
C4 clocks use different edges to mark bit boundaries.
Figure 7 shows the MT8982 used in a primary rate
serial control application. The MT8982 is used as
the control interface from a microcontroller to
MITEL’s MH89760/790 T1 Primary Rate Interfaces
using the microcontroller’s serial microport. The
MT8982 offloads signalling and trunk control
functions from the central switch matrix leaving more
capacity for switching.
To program a connection between a ST-BUS channel
and a GCI channel, some channel conversion is
necessary.
Figure 11 shows the relationship
between the ST-BUS basic access frame and the
GCI basic access frame. Because the MT8982 shifts
the GCI frame pulse (input or output) by five
channels, all of the GCI channels must be
incremented by five to be correctly addressed by the
CENTRAL DKTS CONTROLLER
MT8972
DNIC
MT8982
MiniDx
MH88630/1
C.O. Trunk
MT8972
DNIC
•
•
•
MT8972
DNIC
Microcontroller
Figure 5 - Digital Key Telephone System (DKTS)
2-38
To
Central
Office
MT8982
ISO-CMOS
MT8982
MiniDx
STi0
STi1
STi0
STo1
Subscriber
Interface 0
CSTi0
•
•
CSTi1
Subscriber
Interface 32
Small Remote Switch 1
µP
MT9080/85’s
Large Switch
Matrix
•
•
•
•
•
•
MT8982
MiniDx
STi0
Large Central Switch &
Central Control
STo0
STi1
Subscriber
Interface 0
STo1
CSTi0
•
•
CSTi1
Subscriber
Interface 32
Small Remote Switch n
Figure 6 - Distributed Switching System
MT8980 Switch
Matrix
STo0
STi0
Parallel
µP Interface
MT8952
D-Channel Protocol
Controller
CDSTo
MH89760/790
T1 Trunk
CDSTi
DSTi
DSTo
Serial
µP Interface
MT8982
MiniDx
CSTi0
STo0
STo1
CSTi1
CSTo
STi0
Figure 7 - Primary Rate Serial Controller
2-39
MT8982
ISO-CMOS
Mitel Basic Rate
Phone Components
MT8982 MiniDx
STo0
STi0
PCM
Streams
STo
STi
STi1
STo1
C4i
GCI CLK
(4.096 MHz)
C4i
F0i
F0o
F0i
ST-BUS Frame Pulse
GCI Frame Pulse
Figure 8 - GCI/ST-BUS Interface
MT8982. Therefore, to connect GCI channel B1 to
ST-BUS channel B1, the MT8982 must be
programmed to connect channel 5 to channel 2. The
five channel offset ensures that all four basic rate
channels will be switched together within one frame
period, regardless which direction the data is being
switched.
F0i
The five channel offset for GCI channels is required
even in GCI to GCI switching systems. For example,
to switch GCI channel B1 to GCI channel B2, the
MT8982 must be programmed to connect channel 5
to channel 6.
Channel 0
Channel 4
Channel 5
C4i
F0o
Figure 9 - ST-BUS/GCI Timing with ST-BUS as Master
Channel 0
F0i
Channel 4
Channel 5
C4i
F0o
Figure 10 - ST-BUS/GCI Timing with GCI as Master
CH0
CH1
CH2
CH3
ST-BUS
D
C
B1
B2
GCI
B1
B2
M
D and C/I
CH0(5)
CH1(6)
CH2(7)
CH3(8)
- ST-BUS and MiniDx Channels
- GCI (MiniDx) Channels
Figure 11 - Switching GCI and ST-BUS Basic Rate Access Channels
2-40
MT8982
ISO-CMOS
Absolute Maximum Ratings*
Parameter
Symbol
1
Power supply voltage VDD-VSS
2
Voltage on any pin
VI
3
Current at any pin (other than supply)
IO
4
Storage temperature
TS
5
Package power dissipation
PD
Min
Max
Units
6
V
VDD+0.3
V
100
mA
+150
°C
1000
mW
VDD-VSS
VSS-0.3
-65
* Exceeding these values may cause permanent damage. Functional operation under these conditions is not implied.
Recommended Operating Conditions - Voltages are with respect to ground (VSS) unless otherwise stated.
Characteristics
Sym
Min
Typ‡
Max
Units
1
Operating Temperature
TOP
-40
+85
°C
2
Power supply
VDD
4.5
5.5
V
3
Input voltage
VI
VSS
VDD
V
Test Conditions
‡ Typical figures are at 25°C and are for design aid only: not guaranteed and not subject to production testing.
DC Electrical Characteristics - Voltages are with respect to ground (VSS) unless otherwise stated.
Characteristics
Sym
Min
Typ‡
Max
Units
1
Operating supply voltage
VDD
4.5
5.0
5.5
V
2
Operating supply current
IDD
2.0
mA
Outputs unloaded
3
Static supply current
IDDS
100
µA
All inputs =VDD
4
High level input
VIH
5
Low level input voltage
VIL
0.8
V
6
Input leakage current
IIH/IIL
10.0
µA
VIN=VSS or VDD
7
Low level output voltage
VOL
0.4
V
IOL = 4.0 mA
8
High level output voltage
VOH
2.4
V
IOH = 2.0 mA
9
Output low (sink) current
IOL
4.0
mA
VOUT=0.4 V
10
Output high (source) current
IOH
2.0
mA
VOUT=2.4V, VDD=4.5V
2.0
Test Conditions
V
‡ Typical figures are at 25°C and are for design aid only: not guaranteed and not subject to production testing.
AC Electrical Characteristics† - Serial Microport (see Figure 12) - Voltages are with respect to ground
(VSS) unless otherwise stated.
Characteristics
Sym
Min
Typ‡
Max
Units
Test Conditions
1
Chip Select Setup Time
tcs
5
ns
2
RxD Input Setup Time
trs
40
ns
3
RxD Input Hold Time
trh
0
ns
4
TxD Output Delay
ttd
80
ns
CL=50pF, RL=1kΩ
5
TxD Output Tristate Delay
tdaz
140
ns
CL=50pF, RL=1kΩ*
6
SCLK Pulse Width High
tppwh
190
ns
7
SCLK Pulse Width Low
tppwl
190
ns
8
Command/Data Byte Delay Time
tcdbd
2
µs
† Timing is over recommended temperature & power supply voltages.
‡ Typical figures are at 25°C and are for design aid only: not guaranteed and not subject to production testing.
* High impedance is measured by pulling to the appropriate rail with RL, with timing corrected to cancel time taken to discharge CL.
2-41
MT8982
ISO-CMOS
tcs
CS
tppwh
tcdbd
tppwl
SCLK
trh
trs
RxD
bit 7
bit 0
TxD
tdaz
ttd
ttd
bit 0
bit 7
Figure 12 - Serial Microport Timing
10 cycles of C4i
F0i
(ST-BUS)
tfs
tfs
tfh
F0i
(GCI)
C4i
tsdaa
tsdaz
tsdza
DSTo0-1
tss
tsh
DSTi0-1
CSTi0-1
Figure 13 - TDM Bus Timing
2-42
tfh
MT8982
ISO-CMOS
AC Electrical Characteristics† - TDM Bus (See Figures 13 and 14a, 14b).
Voltages are with
respect to ground (VSS) unless otherwise stated.
Characteristics
Sym
Min
1
Frame Pulse Input Setup Time
tfs
10
2
Frame Pulse Input Hold Time
tfh
5
Typ‡
Max
Units
Test Conditions
ns
4 meg mode
5
ns
cycles
3
Serial Output Delay;
Active to Active
tsdaa
100
ns
CL=50pF
4
Serial Output Delay;
Active to High Z
tsdaz
200
ns
CL=50pF
RL=1kΩ*
5
Serial Output Delay;
High Z to Active
tsdza
150
ns
CL=150pF
6
Serial Input Setup Time
tss
20
ns
7
Serial Input Hold Time
tsh
10
ns
8
Frame Pulse Output Delay
tfd
70
ns
9
ODE Low to Serial Out High Z
tsaz
125
ns
CL=50pF, RL=1kΩ*
10
ODE High to Serial Out Active
tsza
50
ns
CL=50pF, RL=1kΩ
11
C4 Clock Pulse Width Low
tc4l
25
100
209
ns
tc4 = 244 ns
12
C4 Clock Pulse Width High
tc4h
35
100
219
ns
tc4 = 244 ns
13
C4 Clock Period
tc4
150
244
ns
† Timing is over recommended temperature & power supply voltages.
‡ Typical figures are at 25°C and are for design aid only: not guaranteed and not subject to production testing.
* High impedance is measured by pulling to the appropriate rail with RL, with timing corrected to cancel time taken to discharge CL.
tfd
tfd
tc4
F0o (ST-BUS)
tc4l
tc4h
C4i
F0o (GCI)
tfd
tfd
Figure 14a - TDM Bus Timing - F0o/Clock Timing
ODE
STo0-1
tsaz
tsza
Figure 14b - ODE Timing
2-43
MT8982
NOTES:
2-44
ISO-CMOS