STMICROELECTRONICS M3488Q1

M3488
256 x 256 DIGITAL SWITCHING MATRIX
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PREL IMINARY DATA
256 INPUT AND 256 OUTPUT CHANNEL
CMOS DIGITAL SWITCHING MATRIX COMPATIBLE WITH M088
BUILDING BLOCK DESIGNED FOR LARGE
CAPACITY ELECTRONIC EXCHANGES, SUBSYSTEMS AND PABX
NO EXTRA PIN NEEDED FOR NOT-BLOCKING SINGLE STAGE AND HIGHER CAPACITY
SYNTHESIS BLOCKS (512 or 1024 channels)
EUROPEAN TELEPHONE STANDARD COMPATIBLE (32 serial channels per frame)
PCM INPUTS AND OUTPUTS MUTUALLY
COMPATIBLE
ACTUAL INPUT-OUTPUT CHANNEL CONNECTIONS STORED AND MODIFIED VIA AN
ON CHIP 8-BIT PARALLEL MICROPROCESSOR INTERFACE
TYPICAL BIT RATE : 2Mbit/s
TYPICAL SYNCHRONIZATION RATE : 8KHz
(time frame is 125µs)
5V P0WER SUPPLY
CMOS & TTL INPUT/OUTPUT LEVELS COMPATIBLE
HIGH DENSITY ADVANCED 1.2µm HCMOS3
PROCESS
DIP40
PQFP44
ORDERING NUMBERS:
M3488B1
M3488Q1
Main instructions controlled by the microprocessor interface
CHANNEL CONNECTION/DISCONNECTION
OUTPUT CHANNEL DISCONNECTION
INSERTION OF A BYTE ON A PCM OUTPUT
CHANNEL/DISCONNECTION
TRANSFER TO THE MICROPROCESSOR OF
A SINGLE PCM OUTPUT CHANNEL SAMPLE
TRANSFER TO THE MICROPROCESSOR OF
A SINGLE OUTPUT CHANNEL CONTROL
WORD
TRANSFER TO THE MICROPROCESSOR OF
A SELECTED 0 CHANNEL PCM INPUT DATA
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ABSOLUTE MAXIMUM RATINGS
Symbol
VCC
Parameter
Supply Voltage
Test Conditions
Unit
-0.3 to 7
V
V
VI
Input Voltage
-0.3 to VCC+0.3
VO
Off State Output Voltage
-0.3 to VCC+0.3
V
IO
Current at Digital Outputs
30
mA
Ptot
Total Package Power Dissipation
1.5
W
Tstg
Storage Temperature Range
-65 to 150
°C
Top
Operating Temperature Range
0 to 70
°C
Stresses above those l isted under ” Absolute Maximum Ratings” may cause permanent damage to the devi ce. This is a stress
rati ngs only and functional operation of the device at these or any other conditions above those indicated in the operating conditions of this specificati on is not implied. Exposure to absolute maximum rating conditions for extended periods may affect devi ce
reliabili ty.
November 1994
1/18
This is advanced information on a new product now in development or undergoing evaluation. Details are subject to change without notice.
M3488
OUT PCM3
N.C.
OUT PCM4
OUT PCM5
41
40
39
38
37
RD
OUT PCM2
42
OUT PCM6
OUT PCM1
43
OUT PCM7
OUT PCM0
44
36
35
34
CLOCK
1
33
N.C.
SYNC
2
32
WR
INP PCM7
3
31
CS1
INP PCM6
4
30
CS2
INP PCM5
5
29
RESET
INP PCM4
6
28
VSS
INP PCM3
7
27
C/D
INP PCM2
8
26
A1
INP PCM1
9
25
S1
INP PCM0
10
24
A2
V CC
11
23
S2
12
13
14
15
16
17
18
19
20
21
22
D7
D6
D5
D4
N.C.
D3
D2
D1
D0
DR
PQFP44
N.C.
DIP40
N.C.
PIN CONNECTIONS (Top views)
EXCHANGE NETWORKS APPLICATIONS
256 PCM links network (160 or 192 DSM) : the 32 x 32 link module shown on the next page.
2048 PCM links network (1792 or 2048 DSM) : the 256 x 256 link network is shown above.
2/18
D93TL040A
M3488
EXCHANGE NETWORKS APPLICATIONS (continued)
Single Stage/Sixteen Devices Configuration (32 by 32 links or 1024 channels).
3/18
M3488
BLOCK DIAGRAM
4/18
M3488
RECOMMENDED OPERATING CONDITIONS
Symbol
Parameter
Value
4.75 to 5.25
V
Vi
Input Voltage
0 to 5.25
V
VO
Off State Input Voltage
0 to 5.25
V
CLOCK
Freq.
Input Clock Frequency
4.096
MHz
8
KHz
0 to 70
°C
VCC
Supply Voltage
Unit
SYNC Freq. Input Synchronization Frequency
Top
Operating Temperature
CAPACITANCES (measurement freq. = 1MHz; Top = 0 to 70°C; unused pins tied to VSS)
Symbol
Parameter
Pins (*)
Min.
Typ.
Max.
Unit
Input Capacitance
6 to 15; 26 to 30; 32 to 36
5
pF
CI/O
I/O Capacitance
20 to 24
15
pF
CO
Output Capacitance
1 to 4; 17 to 19; 25; 37 to 40
10
pF
Max.
Unit
V
CI
D.C. ELECTRICAL CHARACTERISTICS (Tamb = 0 to 70°C, VCC = 5V ±5%)
All D.C. characteristics are valid 250µs after VCC and clock have been applied.
Symbol
Parameter
Pins (*)
Test Condition
Min.
Typ.
VILC
Clock Input Low Level
6
-0.3
0.8
VIHC
Clock Input High Level
6
2.4
VCC
V
VIL
Input Low Level
7 to 15
20 to 24
26 to 30
32 to 36
-0.3
0.8
V
VIH
Input High Level
7 to 15
20 to 24
26 to 30
32 to 36
2
VCC
V
VOH
Output High Voltage (Level)
17 to 25
IOH
Output High Current
VOL
Output Low Voltage (Level)
IOL
Output Low Current
IIL
IOH = 5mA
2.4
V
VOH = 2.4V
5
mA
1 to 4
37 to 40
17 to 25
IOL = 5mA
Input Leakage Current
6 to 15
26 to 30
32 to 36
VIN = 0 to VCC
5
µA
IDL
Data Bus Leakage Current
17 to 24
VIN = 0 to VCC
VCC applied; Pins 35
and 36 tied to VCC,
after Device Initialization
±5
µA
ICC
Supply Current
16
Clock Freq. = 4.096MHz
30
mA
VOL = 0.4V
0.4
5
V
mA
15
(*) T he pi n number i s referred to the DIP 40 ver sion.
5/18
M3488
A.C. ELECTRICAL CHARACTERISTICS (Tamb = 0 to 70°C, VCC = 5V ±5%)
All A.C. characteristics are valid 250µs after VCC and clock have been applied. CL is the max. capacitive load.
Signal
Symbol
Min.
Typ.
CK (clock)
tCK
tWL
tWH
tR
tF
Clock Period
Clock Low Level Width
Clock High Level Width
Rise Time
Fall Time
230
100
100
244
SYNC
(frame pulse)
tSL
tHL
tSH
tWH
Low Level Setup Time
Low Level Hold Time
High Level Setup Time
High Level Width
60
30
80
tCK
ns
ns
ns
ns
PCM Input
Busses
tS
tH
Setup Time
Hold Time
5
+40
ns
ns
PCM Output
Busses
Open Drain
tPD min
tPD max
Parameter
Propagation time
referred to CK low level
Propagation time
referred to CK high level
RESET
tSL
tHL
tSH
tWH
Low Level Setup Time
Low Level Hold Time
High Level Setup Time
High level Width
WR, RD
tWL
tWH
tREP
Low Lvel Width
High Level Width
Repetition Interval
between Active Pulses
High Level Setup Time
to Active Read Strobe
High Level Hold Time
from Active Write Strobe
Rise Time
Fall Time
tSH
tHH
tR
tF
6/18
Test Condition
45
C L = 150pF
RL = 1K
Max.
Unit
25
25
ns
ns
ns
ns
ns
110
110
ns
140
60
30
80
tCK
ns
ns
ns
ns
ns
ns
ns
ns
100
tCK
see
formula
0
tREP 40 + 2 tCK + tWL(CK) +
+ tR(CK)
15
ns
ns
60
60
ns
ns
M3488
A.C. ELECTRICAL CHARACTERISTICS (continued)
Signal
Symbol
CS1, CS2
tSL(CS-WR)
tHL(CS-WR)
tSH(CS-WR)
tHH(CS-WR)
tSL(CS-RD)
tHL(CS-RD)
tSH(CS-RD)
tHH(CS-RD)
C/D
tS(C/D-WR)
tH(C/D-WR)
tS(C/D)-RD)
tH(C/D-RD)
A1, S1,
A2, S2
(match
inputs)
tS(match-WR)
tH(match-WR)
tS(match-RD)
tH(match-RD)
DR
(data
ready)
tW
tPD
D0 to D7
(interface
bus)
tS(BUS-WR)
tH(BUS-WR)
tPD(BUS)
tHZ(BUS)
Parameter
Low level setup time
to WR falling edge
Low Level hold time
from WR rising edge
High Level setup time
to WR falling edge
High level hold time
from WR rising edge
Low level setup time
to RD falling edge
Low level hold time
from RD rising edge
High level setup time
RD falling edge
High level hold time
from RD
Test Condition
Max.
Unit
ns
Active Case
0
ns
Inactive Case
0
ns
Inactive Case
0
ns
Active Case
0
ns
Active Case
0
ns
Inactive Case
0
ns
Inactive Case
0
ns
130
ns
15
ns
20
ns
Setup time to write
strobe end
Hold time from
strobe end
Setup time to read
strobe start
Hold time from read
strobe end
20
ns
130
ns
15
ns
20
ns
20
ns
Instructions 5 and 6
Instruction 5, CL =
150pF
Input setup time to
write strobe end
Input hold time
from write strobe end
Propagation time
from (active) falling
Edge of read strobe
Propagation time
from (active) rising
Edge of read strobe
to high impedance state
Typ.
0
Setup time to write
strobe end
Hold time from
write strobe end
Setup time to read
strobe start
Hold time from read
strobe end
Low state width
DR output delay
from write strobe end
(active command)
Min.
Active Case
C L = 200pF
4.tCK
2.tCK
ns
7.tCK
ns
130
ns
15
ns
120
ns
80
ns
C L = 200pF
A.C. TESTING, OUTPUT WAVEFORM
A.C. testing inputs are driven at 2.4V for a logic ”1” and 0.45V for a logic ”0”, timing measurement are made at
2.0V for a logic ”1”and 0.8V for a logic ”0”.
7/18
M3488
PCM TIMING, RESET, SYNC
WRITE OPERATION TIMING
8/18
M3488
READ OPERATION TIMING
GENERAL DESCRIPTION
The M3488 is intendedfor large telephoneswitching
systems, mainly central exchanges, digital line concentrators and private branch exchanges where a
distributed microcomputer control approach is extensively used. It consists of a speech memory
(SM), a control memory (CM), a serial/parallel and
a parallel/serial converter, an internal parallel bus,
an interface (8 data lines, 11 control signals) and
dedicated control logic.
By means of repeated clock division two timebases
are generated. These are preset from an external
synchronization signal to two specific count numbers so that sequential scanning of the bases give
synchronous addresses to the memories and I/O
channel controls. Different preset count numbers
are needed because of processing delays and
data path direction. The timebase for the input channels is delayed and the timebase for output channels is advanced with respect to the actual time.
Each serial PCM input channel is converted to parallel data and stored in the speech memory at the
beginning of any new time slot (according to first
timebase) in the location determined by input pin
number and time slot number. The control memory
CM maintains the correspondencesbetween input
and output channels. More exactly, for any output
pin/outputchannel combination the control memory
gives either the full address of the speech memory
location involved in the PCM transfer or an 8-bit
word to be supplied to the parallel/serial output converter. A 9th bit at each CM location defines the data
source for output links, low for SM, high for CM.
The late timebase is used to scan the output channels and to determine the pins to be serviced within
each channel ; enough idle cycles are left to the microprocessor for asynchronousinstruction processing.
Two 8-bit registers OR1 and OR2 supply feedback
data for control or diagnosticpurposes ; OR1 comes
from internal bus i.e. from memories, OR2 gives an
opcode copy and additional data to the microcomputer. A four byte-five bit stack register and an instruction register, under microcomputer control,
store input data available at the interface.
Dedicated logic, under controlof the microprocessor
interface, extracts the 0 channel content of any selected PCM input bus, using spare cycles of SM.
9/18
M3488
PINS FUNCTION
Pin Assignement
Symbol
D7 to D0
C/D
Name
Data bus
Input control
A1, S1, A2, S2 Address select or match
CS1, CS2
Chip select
DIP40
PQFP44
17 to 24
13 to 21
30
27
26 to 29
23 to 26
33, 34
30, 31
WR
Data transfer enable
35
32
RD
Read enable
36
34
DR
Data ready
25
22
RESET
RESET control
32
29
CLOCK
Input master clock
6
1
Input synchronization
7
2
8 to 15
3 to 10
37 to 40 and
1 to 4
35 to 38 and
40 to 43
SYNC
IN PCM 7 to 0 PCM input bus
OUT PCM 7
to 0
10/18
PCM output bus
M3488
PIN DESCRIPTION
D7 to D0
Data bus pins. The bidirectional bus is usedto transfer dataand instructions to/fromthe microprocessor.
D0 is the least significant digit. The output bus is 8
bits wide ; input is only 5 bits wide. (D4 to D0)
The bus is tristate and cannot be used while RESET
is held low.
The meaning of input data, such as bus or channel
numbers, and of expected output data is specified
in detail by the instruction description. (Pagg. 12-14)
C/D (pin 30)
Input control pin, select pin. In a write operation
C/D = 0 qualifies any bus content as data, while
C/D = 1 qualifies it as an opcode. In a read operation
OR1 is selected by C/D = 0, OR2 by C/D = 1.
A1, S1, A2, S2
Address select or match pins. In a multi-chip configuration (e.g. a single stage matrix expansion), using the same CS pins, the match condition (A1 = S1
and A2 = S2) leaves the commandinstruction as defined; on the contrary the mismatch condition modifies the execution as follows : instructions 1 and 3
are reversed to channeldisconnection, instruction 5
is unaffected, instructions 2-4-6 are cancelled (not
executed).
Bus reading takes place only on match condition,
instruction flow is in any case affected.
Eachpins couple is commutative : in a multichip configuration pins S1 and S2 give a hard-wired address
selection for individual matrixes, while in single configuration S1 and A1 or S2 and A2 are normally
tied together.
CS1, CS2
Commutative chip select pins. They enable the device to perform valid read/write operations (active
low). Two pins allow row/column selection with different types of microprocessors ; normally one is
tied to ground.
WR
Pin WR, when CS1 and CS2 are low, enables data
transfer from microprocessor to the device. Data or
opcode and controls are latchedon WR rising edge.
Becauseof internal clock resynchronizationone single additionalrequirement is recommended in order
to produce a simultaneous instruction execution in
a multichip configuration: WR rising edge has to be
20 to 20 + tWL(CK) nsec late relative to clock falling
edge.
RD
When CS1 andCS2 are low and match condition exists, a low level on RD enables a register OR1 or
OR2 read operation, through the bidirectional bus.
In addition, the rising edge of RD latches C/D and
the match condition pins in order to direct the internal flow of operations. Because of internal clock
resynchronization, one single additional requirement is recommended in order to produce a simultaneousinstruction flow in a multichip configuration:
the RD rising edge has to be 20 to 20 + tWL(CK) nsec
late relative to clock falling edge.
DR
Data ready. Normally high, DR output pin goes low
to tell the microprocessor that :
a) the instruction code was found to be invalid ;
b) executing instruction 5 an active output channel
was found in the whole matrix array, that is a CM
word not all ”ones” was found in a configuration of
devices sharing the same CS pins ;
c) executing instruction 6 ”0 channel extraction” took
place and OR2 was loaded with total number of
messages inserted on 0 time slot.
DR is active low about two clock cycles in case b
and c ; in case a it is left low until a valid instruction
code is supplied.
RESET
RESET control pin is normally used at the very beginning to initialize the device or the network. Any
logical status is reset andCM is set to all ”ones” after
RESET going low.
The internal initialization routine takes one time
frame whatever the RESET width on low level (minimum one cycle roughly), but it is repeatedan integer
number of time frames as long as RESET is found
low during 0 time slot.
Initialization pulls the interface bus immediately to a
high impedance state. After the CM has been set to
all ”ones” the PCM output channels are also set to
high impedance state.
CLOCK
Input master clock. Typical frequency is 4.096MHz.
First division gives an internal clock controlling the
input and output channels bit rate.
SYNC
Input synchronization signal is active low. Typical
frequency is 8kHz.
11/18
M3488
Internal time bases are forced by synchronism to an
assigned count number in order to restore channels
and bit sequential addressing to a known state.
Count difference between the bases is 32, correspondingto two time slots, that is the minimum PCM
propagation time, or latency time.
INP PCM 7 to INP PCM 0
PCM input busses or pins ; they accept a standard
2Mbit/s rate. Bit 1 (sign bit) is the first of the serial
sequence ; in a parallel conversion it is left adjusted
as the most significant digit.
OUT PCM 7 to OUT PCM 0
PCM output busses or pins ; bit rate and organization are the same as input pins.
Output buffers are open drain CMOS .
The device drives the output channels theoretically
one bit time before they can be exploited as logical
input channels (bit and slot compatibility is preserved): this feature allows inputs and outputs to be
tied together cancelling any analog delay of digital
outputs up to
tDEL max = tbit - tPD(PCM)max + tPD(PCM)min
MIXED RD and WR OPERATIONS
In principle RD and WR operations are allowed in
any order within specification constraints.
In practive, only one control pin is low at any given
time when CS1 and CS2 are enabled.
If by mistake or hardware failure both RD and WR
pins are low, the interface bus is internally pushed
to tristate condition as long as WR is held low and
input registers are protected.
Registers OR1 and OR2 can be read in any order
with a single RD strobe using C/D as multiplexing
control ; never the less this procedure is not recommended because the device is directed for instruction flow only according to data latched by RD rising
edge.
Multiple RD operationsof the same kind are allowed
without affecting the instruction flow : only ”new”
OR1 or OR2 read operations step the flow.
Input and output registers are held for sure in the
previous state for the first 3 cycles following an opcode or an OR2 read.
FUNCTIONAL DESCRIPTION OF SPECIFIC MICROPROCESSOR OPERATIONS
The device, under microprocessor control, performs
the following instructions :
1 CHANNEL CONNECTION
2 CHANNEL DISCONNECTION
3 LOADING OF A BYTE ON A PCM OUTPUT
CHANNEL
4 TRANSFER OF A SINGLE PCM OUTPUT
CHANNEL SAMPLE
5 TRANSFER OF A SINGLE OUTPUT
CHANNEL CONTROL WORD
6 TRANSFER OF A SELECTED 0 CHANNEL PCM
INPUT DATA ACCORDING TO AN 8-BIT MASK
PREVIOUSLY STORED IN THE ”EXPECTED
MESSAGES” REGISTER
The instruction flow is as follows.
Any input protocol is started by the microprocessor
interface loading the internal stack register with 2
bytes (4 bytes for instructions 1 and 3) qualified as
data bytes by C/D = 0 and a specific opcode qualified by C/D = 1 (match condition is normally
needed).
12/18
After the code is loaded in the instruction register it
is immediately checked to see whether it is acceptable and if not it is rejected. If accepted the
instruction is also processed as regards match condition and is appended for execution during the
memories’ spare cycles.
Four cases are possible :
a) the codeis not valid ; executioncannottake place,
the DR output pin is reset to indicate the error ; all
registers are saved ;
b) the code is valid for types 2, 4 and 6 but it is unmatched ; execution cannot take place, DR is not affected.
c) the code is valid for types 1 and 3 and it is unmatched ; the instruction is interpreted as a channel
disconnection.
d) the code is valid and is either matched or of type
5 ; the instruction is processed as received.
Validation control takes only two cycles out of a total
executiontime of 4 to 7 cycles ; the last operation is
updating of the content of registers OR1 and OR2,
according to the following instruction tables.
M3488
During a very long internal operation (device initialization after RESET going high or execution of instruction 6) a new set of data bytes with a valid opcode is accepted while a wrong code is rejected. At
the end of the current routine execution takes place
in the same way as described before.
At the end of an instruction it is normally recommended to read one or both registers. To exploit instruction 6, however, it is mandatoryto read register
OR2. This is because instruction 6, used between
other short instructions of type 1 to 5, must have priority and can be enabled only after the short instructions have been completed. Instruction 6 normally
has a long process and a special flow which is described below.
First a not-all-zero mask is stored in the ”expected
messages” register and in another ”background”
register. This operation starts the second phase of
instruction 6 which is called ”channel 0 extraction”
and is repeated at the beginning of any new time
frame.At the beginningof the time frame a new copy
of activated channels to be extracted is made from
the ”background register” and put in the ”expected
messages” register. In addition the latter register is
modified to indicate the exact number of messages
that have arrived. The term messages covers any
input 0 channeldata with startingsequencedifferent
from the label 01. So using this label the number of
expected messages can be reduced to correspond
to the number of effective messages. If and only if
the residual number is different from zero will the de-
vice start the extraction protocol at the end of the
current routine.
The procedureis as follows : the DR outputis pulsed
low as a two cycle interrupt request and OR2 is
loaded with the total number of active channels to
be extracted.
The transfer of OR2 content to the microprocessor
continues the extraction which consists of repeated
steps of OR1 and OR2 loading, indicating respectively the message and the incoming bus number.
Reading the registers in the order OR1, OR2 must
be continued until completion or until the time frame
runs out.
With a new time frame a new extraction process begins, resuming the copy operation from the background register.
During extraction the active channels are scanned
from the highest to the lowest number (from 7 to 0).
While extraction is being carried out the time interval
requirements between active rising edges of RD are
minimum 4 to 7 tCK for sequence OR2 - OR1 and
minimum 2 times tCK for sequenceOR1 - OR2. More
details are given in the following tables.
INSTRUCTION TABLES
The most significant digits of OR2 A7, A6, A5 are a
copy of the PCM selected output bus ; the least significant digits of OR2 are the opcode, C8 is the control bit. In any case parentheses() define actual register content.
INSTRUCTION 1: CHANNEL CONNECTION
Control Signals
Match C/D
CS
Data Bus
WR RD
D7
D6
D5
D4
D3
D2
D1
D0
Notes
st
X
0
0
0
1
X
X
X
X
X
Bi2
Bi1
Bi0
1 Data Byte: selected input bus.
X
0
0
0
1
X
X
X
Ci4
Ci3
Ci2
Ci1
Ci0
2
x
0
0
0
1
X
X
X
X
X
X
0
0
0
1
X
X
X
yes/no
1
0
0
1
X
X
Co4 Co3 Co2 Co1 Co0 4th Data Byte: selected output channel.
X
X
0
0
C4
1
Ci4
C3
1
Ci3
C2
1
Ci2
C8
1
0
0
0
0
0
0
0
yes
0
0
1
0
yes
1
0
1
0
A7 A6 A5
(Bo2 Bo1 Bo0
(Bo2 Bo1 Bo0
Data Byte: selected input channel.
Bo2 Bo1 Bo0 3 rd Data Byte: selected output bus.
C5
1
Bi0
C7 C6
(1
1
(Bi2 Bi1
nd
0
1
Instruction Opcode
C1 C0 OR1: CM content copy, that is,
1
1) for mismatch condition,
Ci1 Ci0) for match condition
0
0
0
1
1)
1)
OR2: that is,
for mismatch condition
for match condition
13/18
M3488
INSTRUCTION2: OUTPUT CHANNEL DISCONNECTION
Control Signals
Match C/D CS
Data Bus
WR
RD
D7
D6
D5
D4
D3
X
X
D2
D1
Notes
D0
st
Bo2 Bo1 Bo0 1 Data Byte: selected output bus.
X
0
0
0
1
X
X
X
X
0
0
0
1
X
X
X
Yes
1
0
0
1
X
X
X
X
0
0
1
0
Instruction Opcode
Yes
0
0
1
0
1
1
1
1
1
1
1
1
OR1: CM Content Copy (output
channel is inactive)
Yes
1
0
1
0
1
1
0
0
1
1
1
1
1
1)
A7 A6 A5
(Bo2 Bo1 Bo0
Co4 Co3 Co2 Co1 Co0 2nd Data Byte: selected output channel.
OR2: that is.
INSTRUCTION3: LOADING ON A PCM OUTPUT CHANNEL FROM A MICROPROCESSOR BYTE
Control Signals
Match C/D CS WR
Data Bus
RD
D7
D6
D5
D4
D3
D2
D1
D0
Notes
st
X
0
0
0
1
X
X
X
X
X
Ci7
Ci6
Ci5
1 Data Byte: most significant digits to
be inserted.
X
0
0
0
1
X
X
X
Ci4
Ci3
Ci2
Ci1
Ci0
2 Data Byte: least significant digits to
be inserted.
X
0
0
0
1
X
X
X
X
X
X
0
0
0
1
X
X
X
Yes/no
1
0
0
1
X
X
X
X
0
1
C5
1
Ci5
C4
1
Ci4
C3
1
Ci3
C2
1
Ci2
1
1
0
0
1
1
nd
Yes
0
0
1
0
C7 C6
(1
1
(Ci7 Ci6
Yes
1
0
1
0
A7 A6 A5
(Bo2 Bo1 Bo0
Bo2 Bo1 Bo0 3rd Data Byte: selected output bus.
Co4 Co3 Co2 Co1 Co0 4th Data Byte: selected output channel..
0
0
Instruction Opcode
C1 C0 OR1: CM content copy, that is,
1
1) for mismatch condition,
Ci1 Ci0) for match condition
1
1
1
1)
OR2: that is.
INSTRUCTION4: TRANSFER OF A SINGLE PCM SAMPLE
Control Signals
Match C/D CS
Data Bus
WR
RD
D7
D6
D5
D4
D3
X
X
D2
D1
Notes
D0
Bo2 Bo1 Bo0 1st Data Byte: selected output bus.
X
0
0
0
1
X
X
X
X
0
0
0
1
X
X
X
Yes
1
0
0
1
X
X
X
X
1
0
1
1
C7
S7
C6
S6
C5
S5
C4
S4
C3
S3
C2
S2
C1
S1
C0
S0
OR1: CM Content Copy if C8 = 1; or
SM Content Sample if C8 = 0
1
1
0
0
1
1
1
1
1
1)
OR2: that is.
Yes
0
0
1
0
Yes
1
0
1
0
A7 A6 A5
(Bo2 Bo1 Bo0
nd
Co4 Co3 Co2 Co1 Co0 2
Data Byte: selected output channel.
Instruction Opcode
Notes : S7...S0 is a parallel copy of a P CM data, S7 is the most significant digit and the first of the sequence.
14/18
M3488
INSTRUCTION5: TRANSFER OF AN OUTPUT CHANNEL CONTROL WORD
Control Signals
Match C/D CS
Data Bus
WR
RD
D7
D6
D5
D4
D3
X
X
D2
D1
Notes
D0
st
Bo2 Bo1 Bo0 1 Data Byte: selected output bus.
X
0
0
0
1
X
X
X
X
0
0
0
1
X
X
X
Yes
1
0
0
1
X
X
X
X
1
0
0
0
Yes
0
0
1
0
C7
C6
C5
C4
C3
C2
C1
C0
OR1: CM selected CM word copy.
Yes
1
0
1
0
1
1
0
0
0
0
0
0)
OR2: that is.
Co4 Co3 Co2 Co1 Co0 2nd Data Byte: selected output channel.
A7 A6 A5 C8
(Bo2 Bo1 Bo0 C8
Instruction Opcode
INSTRUCTION6: CHANNEL 0 SELECTION MASK STORE/DATA TRANSFER
Control Signals
Match C/D CS
Data Bus
WR
RD
D7
D6
D5
D4
D3
X
X
X
0
0
0
1
X
X
X
X
0
0
0
1
X
X
X
Yes
1
0
0
1
X
X
X
N2
N1
N0
D2
D1
Notes
D0
Mi7 Mi6 Mi5
1st Data Byte: most sign. digits of
selection mask.
Mi4 Mi3 Mi2 Mi1 Mi0
2 Data Byte: least sign. digits of
selection mask.
nd
X
1
1
1
0
Instruction Opcode
1
0
OR2: see below.
OR2: see below.
Mask store control
Yes
0
0
1
0
Yes
1
0
1
0
(previous content)
Tn
1
1
OR1: register is not affected.
First Data Transfer (after DR going low)
Yes
0
0
1
0
Yes
1
0
1
0
(previous content)
N2
N1
N0
Tn
OR1: register is not affected.
1
1
1
0
Repeated Data Transfer (after first OR2 transfer)
Yes
0
0
1
0
S7
S6
S5
S4
S3
S2
S1
S0
Yes
1
0
1
0
P2
P1
P0
Fn
1
1
1
0
OR1: expected message stored in SM.
OR2: see below.
No tes : 1.
2.
3.
4.
About mask bits Mi0 to Mi7 a logic ”0” level means disabling condition, a logic ”1” level means enabling condition.
A null mask or a RESET pulse clear the mask and the deep background mask registers and disable channel 0 extraction function.
Reading of OR2 is optional after mask store or redefinition, because function is activated only by not-null mask writing.
After mask store (N2 N1 N0) is the sum of activated channels, after DR is the sum of active channels ; Tn = 1/0 means activation/suppression of the function after store while after DR only Tn = 1 can appear to tell a not-null configuration to be extracted.
5. Reading of OR2 is imperative after DR in order to step the data transfer ; reading of OR1 is also needed to scan in descending order
the priority register. Relevant messages only are considered, that means only messages with a MSD label different from 0 1.
6. (P2 P1 P0) is the PCM bus on which the message copied in OR1 was found ; Fn is a continuation bit telling respectively on level 1/0
for any more/no more extraction step to be performed.
M3488 WITH LESS PCM LINKS THAN 32
CHANNELS
SYNC and the first clock (CK) bit contained in the
slot time for bit 0 of channel 0.
It is also possible to use M3488 when the PCM
frames are made up of a number of channels other
than 32.
In order to use M3488 with these frames, it is sufficient, using the data bytes sent by the microprocessor, to modify the numbering of a few channels.
Suppose that the PCM frames are made up of NChannels, which will be numbered from 0 to (N-1).
In particular :
a) in all instructions in which reference is made to the
input channel (N-1), the number 31 should be
substituted for the number (N-1) ;
b) in all instructions in which reference is made to the
output channel 0, the number N should be substituted for the number 0.
Each PCM frame will thus be made up of a number
of bits multiplied by 8 ; this exactly equal to (N . 8).
Also, in this case, it is necessary to respect the timing relationshipbetween the different signals shown
on the data sheet ; in particular, a relation-ship is always carefully made between the rising edge of
15/18
M3488
PQFP44 (10 x 10) PACKAGE MECHANICAL DATA
mm
DIM.
MIN.
inch
TYP.
MAX.
A
MIN.
TYP.
MAX.
2.45
A1
0.25
A2
1.95
B
0.096
0.010
2.00
2.10
0.077
0.079
0.30
0.45
0.012
0.018
c
0.13
0.23
0.005
0.009
D
12.95
13.20
13.45
0.51
0.52
0.53
D1
9.90
10.00
10.10
0.390
0.394
0.398
D3
8.00
0.315
e
0.80
0.031
0.083
E
12.95
13.20
13.45
0.510
0.520
0.530
E1
9.90
10.00
10.10
0.390
0.394
0.398
E3
8.00
L
0.65
0.315
0.80
L1
0.95
0.026
0.031
1.60
0.037
0.063
K
0°(min.), 7°(max.)
D
D1
A
D3
A2
A1
33
23
22
34
0.10mm
.004
44
B
E
E1
B
E3
Seating Plane
12
11
1
C
L
L1
e
K
PQFP44
16/18
M3488
DIP40 PACKAGE MECHANICAL DATA
mm
DIM.
MIN
TYP
inch
MAX
MIN
TYP
a1
0.63
0.025
b
0.45
0.018
b1
0.23
b2
0.31
1.27
D
E
0.009
0.012
0.050
52.58
15.2
16.68
2.070
0.598
0.657
e
2.54
0.100
e3
48.26
1.900
F
MAX
14.1
0.555
I
4.445
0.175
L
3.3
0.130
17/18
M3488
Information furnished is believed to be accurate and reliable. However, SGS-THOMSON Microelectronics assumes no responsibility for
the consequences of use of such information nor for any infringement of patents or other rights of third parties which may result from its
use. No license is granted by implication or otherwise under any patent or patent rights of SGS-THOMSON Microelectronics. Specification
mentioned in this publication are subject to change without notice. This publication supersedes and replaces all information previously
supplied. SGS-THOMSON Microelectronics products are not authorized for use as critical components in life support devices or systems
without express written approval of SGS-THOMSON Microelectronics.
 1996 SGS-THOMSON Microelectronics – Printed in Italy – All Rights Reserved
SGS-THOMSON Microelectronics GROUP OF COMPANIES
Australia - Brazil - Canada - China - France - Germany - Hong Kong - Italy - Japan - Korea - Malaysia - Malta - Morocco The Netherlands - Singapore - Spain - Sweden - Switzerland - Taiwan - Thailand - United Kingdom - U.S.A.
18/18