PHILIPS SCC2681T

INTEGRATED CIRCUITS
SCC2681T
Dual asynchronous receiver/transmitter
(DUART)
Product data
2004 Apr 06
Philips Semiconductors
Product data
Dual asynchronous receiver/transmitter (DUART)
SCC2681T
• Programmable baud rate for each receiver and transmitter
DESCRIPTION
The Philips Semiconductors SCC2681 Dual Universal
Asynchronous Receiver/Transmitter (DUART) is a single-chip
MOS-LSI communications device that provides two independent
full-duplex asynchronous receiver/transmitter channels in a single
package. The SCC2681T features a faster bus cycle time than the
standard SCC2681. The quick bus cycle eliminates or reduces the
need for wait states with fast CPUs and permits high throughput in
I/O intensive systems. Higher external clock rates may be used with
the transmitter, receiver and counter timer which in turn provide
greater versatility in baud rate generation. The SCC2681T interfaces
directly with microprocessors and may be used in a polled or
interrupt driven system. It is manufactured in CMOS technology.
selectable from:
– 22 fixed rates: 50 to 115.2 k baud
– Non-standard rates to 115.2
– Non-standard user-defined rate derived from programmable
counter/timer
– External 1× or 16× clock
• Parity, framing, and overrun error detection
• False start bit detection
• Line break detection and generation
• Programmable channel mode
The operating mode and data format of each channel can be
programmed independently. Additionally, each receiver and
transmitter can select its operating speed as one of eighteen fixed
baud rates, a 16× clock derived from a programmable counter/timer,
or an external 1× or 16× clock. The baud rate generator and
counter/timer can operate directly from a crystal or from external
clock inputs. The ability to independently program the operating
speed of the receiver and transmitter make the DUART particularly
attractive for dual-speed channel applications such as clustered
terminal systems.
– Normal (full-duplex)
– Automatic echo
– Local loopback
– Remote loopback
• Multi-function programmable 16-bit counter/timer
• Multi-function 7-bit input port
– Can serve as clock or control inputs
– Change of state detection on four inputs
Each receiver is quadruple buffered to minimize the potential of
receiver over-run or to reduce interrupt overhead in interrupt driven
systems. In addition, a flow control capability is provided to disable a
remote DUART transmitter when the receiver buffer is full.
– 100 kΩ typical pull-up resistors
• Multi-function 8-bit output port
– Individual bit set/reset capability
Also provided on the SCC2681T are a multipurpose 7-bit input port
and a multipurpose 8-bit output port. These can be used as general
purpose I/O ports or can be assigned specific functions (such as
clock inputs or status/interrupt outputs) under program control.
– Outputs can be programmed to be status/interrupt/DMA signals
– Auto 485 turn-around
• Versatile interrupt system
– Single interrupt output with eight maskable interrupting
conditions
For a complete functional description and programming information
for the SCC2681T, refer to the SCC2681 product specification.
– Output port can be configured to provide a total of up to six
separate wire-ORable interrupt outputs
• Maximum data transfer rates:
FEATURES
• Fast bus cycle times reduce or eliminate CPU wait states
• Dual full-duplex asynchronous receiver/transmitters
• Quadruple buffered receiver data registers
• Programmable data format
– 1× – 1 MB/sec transmitter and receiver
– 16× – 500 kB/sec receiver and 250 kB/sec transmitter
• Automatic wake-up mode for multidrop applications
• Start-end break interrupt/status
• Detects break which originates in the middle of a character
• On-chip crystal oscillator
• Single +5 V power supply
• Commercial temperature range
– 5 to 8 data bits plus parity
– Odd, even, no parity or force parity
– 1, 1.5 or 2 stop bits programmable in 1/16-bit increments
• 16-bit programmable Counter/Timer
ORDERING INFORMATION
VCC = +5 V ± 10%, Tamb = 0 °C to +70 °C
DESCRIPTION
44-Pin Plastic Lead Chip Carrier (PLCC)
NOTE: For a full register description and programming information see the SCC2681.
2004 Apr 06
2
SCC2681TC1A44
DWG #
SOT187-2
Philips Semiconductors
Product data
Dual asynchronous receiver/transmitter (DUART)
SCC2681T
BLOCK DIAGRAM
8
D0–D7
CHANNEL A
BUS BUFFER
TRANSMIT
HOLDING REG
TxDA
TRANSMIT
SHIFT REGISTER
RDN
OPERATION CONTROL
WRN
ADDRESS
DECODE
CEN
A0–A3
RESET
RECEIVE
HOLDING REG (3)
RxDA
4
RECEIVE
SHIFT REGISTER
R/W CONTROL
MRA1, 2
CRA
SRA
INTERRUPT CONTROL
INTRN
IMR
INTERNAL DATABUS
TIMING
BAUD RATE
GENERATOR
RxDB
CONTROL
TIMING
TxDB
CHANNEL B
(AS ABOVE)
ISR
INPUT PORT
CHANGE OF
STATE
DETECTORS (4)
7
IP0-IP6
IPCR
ACR
CLOCK
SELECTORS
COUNTER/
TIMER
OUTPUT PORT
FUNCTION
SELECT LOGIC
X1/CLK
XTAL OSC
8
OP0-OP7
OPCR
X2
OPR
CSRA
CSRB
ACR
U
CTLR
CTLR
VCC
GND
SD00099
Figure 1. Block Diagram
NOTE:
Refer to SCC2681 for functional description.
2004 Apr 06
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Philips Semiconductors
Product data
Dual asynchronous receiver/transmitter (DUART)
SCC2681T
CEN
RESET
X2
X1/CLK
RxDA
n.c.
TxDA
OP0
OP2
OP4
OP6
39
38
37
36
35
34
33
32
31
30
29
PIN CONFIGURATION
IP2 40
28
D0
IP6 41
27
D2
IP5 42
26
D4
IP4 43
25
D6
24
INTRN
VCC 44
SCC2681TC1A44
14
15
16
17
OP1
OP3
OP5
OP7
D1
13
D3
18
TxDB
19
6
11
5
A2
12
IP1
n.c.
D5
RxDB
D7
20
9
21
4
10
3
A1
RDN
IP3
WRN
GND
8
n.c.
22
7
23
2
A3
1
A0
IP0
n.c.
SD00737
Figure 2. Pin configuration
PIN DESCRIPTION
MNEMONIC
PIN
TYPE
D0–D7
21, 25, 20,
26, 19, 27,
18, 28
I/O
Data Bus: Bidirectional three-state data bus used to transfer commands, data and status between the
DUART and the CPU. D0 is the least significant bit.
NAME AND FUNCTION
CEN
39
I
Chip Enable: Active LOW input signal. When LOW, data transfers between the CPU and the DUART
are enabled on D0–D7 as controlled by the WRN, RDN, and A0–A3 inputs. When CEN is HIGH, the
DUART places the D0–D7 lines in the three-state condition.
WRN
9
I
Write Strobe: When LOW and CEN is also LOW, the contents of the data bus is loaded into the
addressed register. The transfer occurs on the rising edge of the signal.
RDN
10
I
Read Strobe: When low and CEN is also LOW, causes the contents of the addressed register to be
presented on the data bus. The read cycle begins on the falling edge of RDN.
A0–A3
2, 4, 6, 7
I
Address Inputs: Select the DUART internal registers and ports for read/write operations.
RESET
38
I
Reset: A HIGH level clears internal registers (SRA, SRB, IMR, ISR, OPR, OPCR), puts OP0–OP7 in the
HIGH state, stops the counter/timer, and puts channels A and B in the inactive state, with the TxDA and
TxDB outputs in the mark (HIGH) state. Clears Test modes, sets MR pointer to MR1.
INTRN
24
O
Interrupt Request: Active-LOW, open-drain output which signals the CPU that one or more of the eight
maskable interrupting conditions are true.
X1/CLK
36
I
Crystal 1: Crystal connection or an external clock input. A crystal of a clock the appropriate frequency
(nominally 3.6864 MHz) must be supplied at all times. For crystal connections see Figure 7, Clock
Timing.
X2
37
I
Crystal 2: Crystal connection. See Figure 7. If a crystal is not used it is best to keep this pin not
connected.
It must not be grounded.
RxDA
35
I
Channel A Receiver Serial Data Input: The least significant bit is received first. ‘Mark’ is HIGH, ‘space’
is LOW.
RxDB
11
I
Channel B Receiver Serial Data Input: The least significant bit is received first. ‘Mark’ is HIGH, ‘space’
is LOW.
2004 Apr 06
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Philips Semiconductors
Product data
Dual asynchronous receiver/transmitter (DUART)
SCC2681T
MNEMONIC
PIN
TYPE
NAME AND FUNCTION
TxDA
33
O
Channel A Transmitter Serial Data Output: The least significant bit is transmitted first. This output is held
in the ‘mark’ condition when the transmitter is disabled, idle, or when operating in local loopback mode.
‘Mark’ is HIGH, ‘space’ is LOW.
TxDB
13
O
Channel B Transmitter Serial Data Output: The least significant bit is transmitted first. This output is
held in the ‘mark’ condition when the transmitter is disabled, idle, or when operating in local loopback
mode. ‘Mark’ is HIGH, ‘space’ is LOW.
OP0
32
O
Output 0: General purpose output, or channel A request to send (RTSAN, active-LOW). Can be
deactivated automatically on receive or transmit.
OP1
14
O
Output 1: General purpose output, or channel B request to send (RTSBN, active-LOW). Can be
deactivated automatically on receive or transmit.
OP2
31
O
Output 2: General purpose output, or channel A transmitter 1× or 16× clock output, or channel A
receiver 1× clock output.
OP3
15
O
Output 3: General purpose output, or open-drain, active-LOW counter/timer interrupt output, or channel
B transmitter 1× clock output, or channel B receiver 1× clock output.
OP4
30
O
Output 4: General purpose output, or channel A open-drain, active-LOW, RxRDYA/FFULLA interrupt
output.
OP5
16
O
Output 5: General purpose output, or channel B open-drain, active-LOW, RxRDYB/FFULLB interrupt
output.
OP6
29
O
Output 6: General purpose output, or channel A open-drain, active-LOW, TxRDYA interrupt output.
OP7
17
O
Output 7: General purpose output, or channel B open-drain, active-LOW TxRDYB interrupt output.
IP0
8
I
Input 0: General purpose input, or channel A clear to send active-LOW input (CTSAN). Pin has an
internal VCC pull-up device supplying 1 to 4 µA of current.
IP1
5
I
Input 1: General purpose input, or channel B clear to send active-LOW input (CTSBN). Pin has an
internal VCC pull-up device supplying 1 to 4 µA of current.
IP2
40
I
Input 2: General purpose input, or counter/timer external clock input. Pin has an internal VCC pull-up
device supplying 1 to 4 µA of current.
IP3
3
I
Input 3: General purpose input, or channel A transmitter external clock input (TxCA). When the external
clock is used by the transmitter, the transmitted data is clocked on the falling edge of the clock. Pin has
an internal VCC pull-up device supplying 1 to 4 µA of current.
IP4
43
I
Input 4: General purpose input, or channel A receiver external clock input (RxCA). When the external
clock is used by the receiver, the received data is sampled on the rising edge of the clock. Pin has an
internal VCC pull-up device supplying 1 to 4 µA of current.
IP5
42
I
Input 5: General purpose input, or channel B transmitter external clock input (TxCB). When the external
clock is used by the transmitter, the transmitted data is clocked on the falling edge of the clock. Pin has
an internal VCC pull-up device supplying 1 to 4 µA of current.
IP6
41
I
Input 6: General purpose input, or channel B receiver external clock input (RxCB). When the external
clock is used by the receiver, the received data is sampled on the rising edge of the clock. Pin has an
internal VCC pull-up device supplying 1 to 4 µA of current.
VCC
44
I
Power Supply: +5 V supply input.
GND
22
I
Ground
n.c.
1, 12, 23,
34
2004 Apr 06
not connected
5
Philips Semiconductors
Product data
Dual asynchronous receiver/transmitter (DUART)
SCC2681T
ABSOLUTE MAXIMUM RATINGS1
PARAMETER
SYMBOL
RATING
UNIT
Tamb
Operating ambient temperature
0 to +70
°C
Tstg
Storage temperature range
–65 to +150
°C
All voltages with respect to GND3
–0.5 to +6.0
V
VSS – 0.5 to VCC + 0.5
V
range2
Pin voltage range
NOTES:
1. Stresses above those listed under Absolute Maximum Ratings may cause permanent damage to the device. This is a stress rating only and
functional operation of the device at these or any other conditions above those indicated in the operation section of this specification is not
implied.
2. For operating at elevated temperatures, the device must be derated based on +150 °C maximum junction temperature.
3. This product includes circuitry specifically designed for the protection of its internal devices from damaging effects of excessive static
charge. Nonetheless, it is suggested that conventional precautions be taken to avoid applying any voltages larger than the rated maxima.
2004 Apr 06
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Philips Semiconductors
Product data
Dual asynchronous receiver/transmitter (DUART)
SCC2681T
DC ELECTRICAL CHARACTERISTICS1, 2, 3
Tamb = 0 °C to +70 °C; VCC = +5.0 V ± 10%
SYMBOL
PARAMETER
VIL
VIH
VIH
VIH
LOW-level input voltage
HIGH-level input voltage (except X1/CLK)
HIGH-level input voltage (except X1/CLK)
HIGH-level input voltage (X1/CLK)
VOL
LOW-level output voltage
VOH
HIGH-level output voltage (except open-drain outputs)4
IIX1
IILX1
IIHX1
X1/CLK input current
X1/CLK input LOW current – operating
X1/CLK input HIGH current – operating
IOHX2
IOHX2S
IOLX2
IOLX2S
X2 output HIGH current – operating
X2 output HIGH short circuit current – operating
X2 output LOW current – operating
X2 output LOW short circuit current – operating
II
Input leakage current:
All except input port pins
Input port pins
IOZH
IOZL
TEST CONDITIONS
Tamb ≥ 0 °C
Tamb < 0 °C
LIMITS
UNIT
Min
Typ
Max
–
2.0
2.5
0.8 VCC
–
–
–
–
0.8
–
–
–
V
V
V
V
IOL = 2.4 mA
–
–
0.4
V
IOH = –400 µA
VCC – 0.5
–
–
V
VIN = 0 V to VCC
VIN = 0 V
VIN = VCC
–10
–75
0
–
–
–
+10
0
75
µA
µA
µA
VOUT = VCC; X1 = 0
VOUT = 0 V; X1 = 0
VOUT = 0 V; X1 = VCC
VOUT = VCC; X1 = VCC
0
–10
–75
1
–
–
–
–
+75
–1
0
10
µA
mA
µA
mA
VIN = 0 V to VCC
VIN = 0 V to VCC
–10
–20
–
–
+10
+10
µA
µA
Output off current HIGH, 3-state data bus
Output off current LOW, 3-state data bus
VIN = VCC
VIN = 0 V
–
–10
–
–
10
–
µA
µA
IODL
IODH
Open-drain output LOW current in off-state
Open-drain output HIGH current in off-state
VIN = 0 V
VIN = VCC
–10
–
–
–
–
10
µA
µA
ICC
Power supply current5
Operating mode
CMOS input levels
–
10
mA
–
NOTES:
1. Parameters are valid over specified temperature range.
2. All voltage measurements are referenced to ground (GND). For testing, all inputs swing between 0.4 V and 2.4 V with a transition time of
5 ns maximum. For X1/CLK this swing is between 0.4 V and 4.4 V. All time measurements are referenced at input voltages of 0.8 V and
2.0 V and output voltages of 0.8 V and 2.0 V, as appropriate.
3. Typical values are at +25 °C, typical supply voltages, and typical processing parameters.
4. Test conditions for outputs: CL = 150 pF, except interrupt outputs. Test conditions for interrupt outputs: CL = 50 pF, RL = 2.7 kΩ to VCC.
5. All outputs are disconnected. Inputs are switching between CMOS levels of VCC – 0.2 V and VSS + 0.2 V.
2004 Apr 06
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Philips Semiconductors
Product data
Dual asynchronous receiver/transmitter (DUART)
SCC2681T
AC ELECTRICAL CHARACTERISTICS1, 2, 3, 4
SYMBOL
LIMITS
PARAMETER
UNIT
Min
Typ
Max
1.0
–
–
µs
0
100
120
110
15
–
10
–
75
35
15
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
100
–
65
–
–
–
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
0
0
–
–
–
–
–
–
200
ns
ns
ns
–
–
–
–
–
–
–
–
–
–
–
–
200
200
200
200
200
200
ns
ns
ns
ns
ns
ns
Reset timing (see Figure 3)
tRES
Reset pulse width
Bus timing (see Figure 4) (Note 5)
tAVEL
tELAX
tRLRH
tEHEL
tRLDA
tRLDV
tRHDI
tRHDF
tWLWH
tDVWH
tWHDI
A0–A3 set-up to RDN and CEN, or WRN and CEN LOW
RDN and CEN, or WRN and CEN LOW to A0–A3 invalid
RDN and CEN LOW to RDN or CEN HIGH
CEN HIGH to CEN LOW6, 7
CEN and RDN LOW to data outputs active
CEN and RDN LOW to data valid
CEN or RDN HIGH to data invalid
CEN or RDN HIGH to data outputs floating
WRN and CEN LOW to WRN or CEN HIGH
Data input valid to WRN or CEN HIGH
WRN or CEN HIGH to data invalid
Port timing (see Figure 5)
tPS
tPH
tPD
Port input set-up time before RDN LOW
Port input hold time after RDN HIGH
Port output valid after WRN HIGH
Interrupt timing (see Figure 6)
tIR
INTRN (or OP3–OP7 when used as interrupts) negated from:
Read RHR (RxRDY/FFULL interrupt)
Write THR (TxRDY interrupt)
Reset command (delta break interrupt)
Stop C/T command (counter interrupt)
Read IPCR (input port change interrupt)
Write IMR (clear of interrupt mask bit)
Clock timing (see Figure 7)
tCLK
X1/CLK HIGH or LOW time
fCLK
X1/CLK frequency
2
tCTC
CTCLK (IP2) HIGH or LOW time
55
fCTC
CTCLK (IP2) frequency8
0
tRX
RxC HIGH or LOW time
55
fRX
RxC frequency
90
(16×)8
0
(1×)8
0
tTX
TxC HIGH or LOW time
fTX
TxC frequency
ns
4
MHz
8
MHz
8
MHz
1
MHz
ns
ns
3.6864
110
ns
(16×)8
0
4
MHz
(1×)8
0
1
MHz
Transmit timing (see Figure 8)
tTXD
TxD output delay from TxC external clock input on IP pin
–
–
300
ns
tTCS
Output delay from TxC LOW at OP pin to TxD data output
0
–
100
ns
Receive timing (see Figure )
tRXS
RxD data set-up time before RxC HIGH at external clock input on IP pin
200
–
–
ns
tRXH
RxD data hold time after RxC HIGH at external clock input on IP pin
25
–
–
ns
NOTES:
1. Parameters are valid over specified temperature range. See Ordering information table for applicable operating temperature range and VCC
supply range.
2. All voltage measurements are referenced to ground (GND). For testing, all inputs except X1/CLK swing between 0.4 V and 2.4 V with a
transition time of 20 ns maximum. For X1/CLK this swing is between 0.4 V and 4.0 V. All time measurements are referenced at input
voltages of 0.8 V and 2.0 V and output voltages of 0.8 V and 2.0 V as appropriate.
3. Typical values are at +25 °C, typical supply voltages, and typical processing parameters.
2004 Apr 06
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Philips Semiconductors
Product data
Dual asynchronous receiver/transmitter (DUART)
SCC2681T
4. Test conditions for outputs: CL = 150 pF, except interrupt outputs. Test conditions for interrupt outputs: CL = 50 pF, RL = 2.7 kΩ to VCC.
5. For bus operations, CEN and RDN (also CEN and WRN) are ANDed internally. As a consequence, the signal asserted last initiates the cycle
and the signal negated first terminates the cycle.
6. If CEN is used as the ‘strobing’ input, the parameter defines the minimum HIGH times between one CEN and the next. The RDN signal must
be negated for tEHEL to guarantee that any status register changes are valid. As a consequence, this minimum time must be met for the
RDN input even if the CEN is used as the strobing signal for bus operations.
7. Consecutive write operations to the same command register require at least three edges of the X1 clock between writes.
8. Minimum frequencies are not tested but are guaranteed by design.
RESET
tRES
SD00028
Figure 3. Reset Timing
A0–A3
tAVEL
tELAX
CEN
(READ)
tEHEL
tRLRH
RDN
tRHDF
tRLDV
tRHDI
tRLDA
D0–D7
(READ)
FLOAT
INVALID
VALID
FLOAT
CEN
(WRITE)
tEHEL
tWLWH
WRN
tDVWH
tWHDI
D0–D7
(WRITE)
VALID
SD00100
Figure 4. Bus Timing
2004 Apr 06
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Philips Semiconductors
Product data
Dual asynchronous receiver/transmitter (DUART)
SCC2681T
RDN
tPH
tPS
IP0–IP6
(a) INPUT PINS
WRN
tPD
OP0–OP7
OLD DATA
NEW DATA
(b) OUTPUT PINS
SD00101
Figure 5. Port Timing
VM
WRN
tIR
INTERRUPT 1
OUTPUT
VOL +0.5V
VOL
NOTES:
1. INTRN or OP3-OP7 when used as interrupt outputs.
2. The test for open drain outputs is intended to guarantee switching of the output transistor. Measurement of this response is referenced from the midpoint of the switching
signal, VM, to a point 0.5V above VOL. This point represents noise margin that assures true switching has occurred. Beyond this level, the effects of external circuitry and
test environment are pronounced and can greatly affect the resultant measurement.
SD00102
Figure 6. Interrupt Timing
2004 Apr 06
10
Philips Semiconductors
Product data
Dual asynchronous receiver/transmitter (DUART)
SCC2681T
tCLK
tCTC
tRx
tTx
+5 V
R1
1 kΩ
X1/CLK
CTCLK
RxC
TxC
X1
U1
tCLK
tCTC
tRx
tTx
RESISTOR REQUIRED
WHEN U1 IS A TTL DEVICE
NC
X2
SCC2681T
C1 = C2 = 24 pF FOR CL = 20 pF
X1
3 pF
50 TO
150 kΩ
3.6864 MHz
X2
TO INTERNAL CLOCK DRIVERS
4 pF
NOTE:
C1 AND C2 SHOULD BE BASED ON MANUFACTURER’S SPECIFICATION. PARASITIC CAPACITANCE SHOULD BE
INCLUDED WITH C1 AND C2. R1 IS ONLY REQUIRED IF U1 WILL NOT DRIVE TO X1 INPUT LEVELS
TYPICAL CRYSTAL SPECIFICATION
FREQUENCY:
2 – 4 MHz
12 – 32 pF
LOAD CAPACITANCE (CL):
TYPE OF OPERATION:
PARALLEL RESONANT, FUNDAMENTAL MODE
SD00726
Figure 7. Clock Timing
1 BIT TIME
(1 OR 16 CLOCKS)
TxC
(INPUT)
tTXD
TxD
tTCS
TxC
(1X OUTPUT)
SD00103
Figure 8. Transmit
RxC
(1X INPUT)
tRXS
tRXH
RxD
SD00104
2004 Apr 06
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Philips Semiconductors
Product data
Dual asynchronous receiver/transmitter (DUART)
SCC2681T
Figure 9. Receive
TxD
D1
D2
D3
BREAK
D4
D6
TRANSMITTER
ENABLED
TxRDY
(SR2)
WRN
D1
D2
D3
START
BREAK
D4
STOP
BREAK
D5 WILL
NOT BE
TRANSMITTED
CTSN1
D6
(IP0)
RTSN2
(OP0)
OPR(0) = 1
OPR(0) = 1
NOTES:
1. Timing shown for MR2(4) = 1.
2. Timing shown for MR2(5) = 1.
SD00094
Figure 10. Transmitter Timing
D1
RxD
D2
D3
D4
D5
D6
D7
D8
D6, D7, D8 WILL BE LOST
RECEIVER
ENABLED
RxRDY
(SR0)
FFULL
(SR1)
RxRDY/
FFULL
(OP5)2
RDN
S
D
S = STATUS
D = DATA
S
D1
D
D2
OVERRUN
(SR4)
D5 WILL
BE LOST
S D
S D
D3
D4
RESET BY
COMMAND
RTS1
(OP0)
OPR(0) = 1
NOTES:
1. Timing shown for MR1(7) = 1.
2. Shown for OPCR(4) = 1 and MR1(6) = 0.
SD00105
Figure 11. Receiver Timing
2004 Apr 06
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Philips Semiconductors
Product data
Dual asynchronous receiver/transmitter (DUART)
MASTER STATION
BIT 9
ADD#1 1
TxD
BIT 9
BIT 9
D0
SCC2681T
ADD#2 1
0
TRANSMITTER
ENABLED
TxRDY
(SR2)
WRN
MR1(4–3) = 11
MR1(2) = 1
ADD#1 MR1(2) = 0 D0
MR1(2) = 1
ADD#2
PERIPHERAL STATION
BIT 9
RxD
0
BIT 9
ADD#1 1
BIT 9
BIT 9
D0
BIT 9
ADD#2 1
0
0
RECEIVER
ENABLED
RxRDY
(SR0)
RDN/WRN
MR1(4–3) = 11
S
D
S = STATUS
D = DATA
S
D
ADD#1
D0
ADD#2
SD00106
Figure 12. Wake-Up Mode
2004 Apr 06
13
Philips Semiconductors
Product data
Dual asynchronous receiver/transmitter (DUART)
PLCC44: plastic leaded chip carrier; 44 leads
2004 Apr 06
SCC2681T
SOT187-2
14
Philips Semiconductors
Product data
Dual asynchronous receiver/transmitter (DUART)
SCC2681T
REVISION HISTORY
Rev
Date
Description
_1
20040406
Product data (9397 750 12073). ECN 853-2446 01-A15014 of 15 December 2003.
Data sheet status
Level
Data sheet status [1]
Product
status [2] [3]
Definitions
I
Objective data
Development
This data sheet contains data from the objective specification for product development.
Philips Semiconductors reserves the right to change the specification in any manner without notice.
II
Preliminary data
Qualification
This data sheet contains data from the preliminary specification. Supplementary data will be published
at a later date. Philips Semiconductors reserves the right to change the specification without notice, in
order to improve the design and supply the best possible product.
III
Product data
Production
This data sheet contains data from the product specification. Philips Semiconductors reserves the
right to make changes at any time in order to improve the design, manufacturing and supply. Relevant
changes will be communicated via a Customer Product/Process Change Notification (CPCN).
[1] Please consult the most recently issued data sheet before initiating or completing a design.
[2] The product status of the device(s) described in this data sheet may have changed since this data sheet was published. The latest information is available on the Internet at URL
http://www.semiconductors.philips.com.
[3] For data sheets describing multiple type numbers, the highest-level product status determines the data sheet status.
Definitions
Short-form specification — The data in a short-form specification is extracted from a full data sheet with the same type number and title. For detailed information see
the relevant data sheet or data handbook.
Limiting values definition — Limiting values given are in accordance with the Absolute Maximum Rating System (IEC 60134). Stress above one or more of the limiting
values may cause permanent damage to the device. These are stress ratings only and operation of the device at these or at any other conditions above those given
in the Characteristics sections of the specification is not implied. Exposure to limiting values for extended periods may affect device reliability.
Application information — Applications that are described herein for any of these products are for illustrative purposes only. Philips Semiconductors make no
representation or warranty that such applications will be suitable for the specified use without further testing or modification.
Disclaimers
Life support — These products are not designed for use in life support appliances, devices, or systems where malfunction of these products can reasonably be
expected to result in personal injury. Philips Semiconductors customers using or selling these products for use in such applications do so at their own risk and agree
to fully indemnify Philips Semiconductors for any damages resulting from such application.
Right to make changes — Philips Semiconductors reserves the right to make changes in the products—including circuits, standard cells, and/or software—described
or contained herein in order to improve design and/or performance. When the product is in full production (status ‘Production’), relevant changes will be communicated
via a Customer Product/Process Change Notification (CPCN). Philips Semiconductors assumes no responsibility or liability for the use of any of these products, conveys
no license or title under any patent, copyright, or mask work right to these products, and makes no representations or warranties that these products are free from patent,
copyright, or mask work right infringement, unless otherwise specified.
 Koninklijke Philips Electronics N.V. 2004
All rights reserved. Printed in U.S.A.
Contact information
For additional information please visit
http://www.semiconductors.philips.com.
Fax: +31 40 27 24825
Date of release: 04-04
For sales offices addresses send e-mail to:
[email protected].
Document order number:
2004 Apr 06
15
9397 750 12073