Intersil CDP6402C Cmos universal asynchronous receiver/transmitter (uart) Datasheet

CDP6402,
CDP6402C
TM
CMOS Universal Asynchronous
Receiver/Transmitter (UART)
March 1997
/Title
DP6
02,
DP64
2C)
ubct
MO
Uniersal
synroous
eceiv
/Tran
itART
Features
Description
• Low Power CMOS Circuitry . . . . . . . . . 7.5mW (Typ) at
3.2MHz (Max Freq.) at VDD = 5V
The CDP6402 and CDP6402C are silicon gate CMOS
Universal Asynchronous Receiver/Transmitter (UART)
circuits for interfacing computers or microprocessors to
asynchronous serial data channels. They are designed to
provide the necessary formatting and control for interfacing
between serial and parallel data channels. The receiver
converts serial start, data, parity, and stop bits to parallel
data verifying proper code transmission, parity and stop bits.
The transmitter converts parallel data into serial form and
automatically adds start parity and stop bits.
• Baud Rate
- DC to 200K Bits/s (Max) at. . . . . . . . . . . . . . 5V, 85oC
- DC to 400K Bits/s (Max) at. . . . . . . . . . . . . . 10V, 85oC
• 4V to 10.5 Operation
• Automatic Data Formatting and Status Generation
• Fully Programmable with Externally Selectable Word
Length (5 - 8 Bits), Parity Inhibit, Even/Odd Parity, and
1, 1-1/2, or 2 Stop Bits
• Operating Temperature Range
- CDP6402D, CD . . . . . . . . . . . . . . . . . -55oC to +125oC
- CDP6402E, CE . . . . . . . . . . . . . . . . . . -40oC to +85oC
• Replaces Industry Type IM6402 and Compatible with
HD6402
Ordering Information
PACKAGE
PDIP
TEMP. RANGE
-40oC to +85oC
Burn-In
utho
SBDIP
Burn-In
eyords
nterorpotion,
MOS
niersal
synroous
eceiv
/Tran
itART
Pinout
5V/200K
BAUD
CDP6402CE
CDP6402CEX
-40oC to +85oC
CDP6402CD
10V/400K
BAUD
PKG.
NO.
E40.6
CDP6402E
CDP6402D
The data word can be 5, 6, 7 or 8 bits in length. Parity may
be odd, even or inhibited. Stop bits can be 1, 1-1/2, or 2
(when transmitting 5-bit code).
The CDP6402 and CDP6402C can be used in a wide range
of applications including modems, printers, peripherals,
video terminals, remote data acquisition systems, and serial
data links for distributed processing systems.
The CDP6402 and CDP6402C are functionally identical.
They differ in that the CDP6402 has a recommended
operating voltage range of 4V to 10.5V, and the CDP6402C
has a recommended operating voltage range of 4V to 6.5V.
D40.6
CDP6402CDX CDP6402DX
CDP6402, CDP6402C (PDIP, SBDIP)
TOP VIEW
VDD
1
40
TRC
NC
2
39
EPE
GND
3
38
CLS1
RRD
4
37
CLS2
RBR8
5
36
SBS
RBR7
6
35
PI
RBR6
7
34
CRL
RBR5
8
33
TBR8
RBR4
9
32
TBR7
RBR3
10
31
TBR6
RBR2
11
30
TBR5
RBR1
12
29
TBR4
PE
13
28
TBR3
FE
14
27
TBR2
OE
15
26
TBR1
SFD
16
25
TRO
RRC
17
24
TRE
DRR
18
23
TBRL
DR
19
22
TBRE
RRI
20
21
MR
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
1-888-INTERSIL or 321-724-7143 | Intersil (and design) is a trademark of Intersil Americas Inc.
Copyright © Intersil Americas Inc. 2001. All Rights Reserved
5-74
File Number
1328.2
CDP6402, CDP6402C
TBR8 (MSB)
TBR1 (LSB)
TRE
TBRL
TRC
TRANSMITTER BUFFER REGISTER
PARITY
LOGIC
TRANSMITTER
TIMING
AND
CONTROL
STOP
TRANSMITTER REGISTER
START
MULTIPLEXER
TRO
CLS1
CLS2
SBS
CONTROL
REGISTER
CRL
EPE
PI
MR
RRI
RRC
DRR
RECEIVER
TIMING
AND
CONTROL
MULTIPLEXER
START
LOGIC
RECEIVER REGISTER
STOP
LOGIC
PARITY
LOGIC
RECEIVER BUFFER REGISTER
THREE
STATE
BUFFERS
SFD
DR
OE
TBRE
FE
PE
RRD
RBR8 (MSB)
FIGURE 1. FUNCTIONAL BLOCK DIAGRAM
5-75
RBR1 (LSB)
CDP6402, CDP6402C
Absolute Maximum Ratings
Thermal Information
DC Supply-Voltage Range, (VDD)
CDP6402 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.5 to +11V
CDP6402C . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .-0.5 to +7V
Input Voltage Range, All Inputs . . . . . . . . . . . . . . -0.5 to VDD +0.5V
DC Input Current, Any One Input . . . . . . . . . . . . . . . . . . . . . . . ±100µA
Device Dissipation Per Output Transistor
For TA = Full Package-Temperature Range
(All Package Types) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100mW
Operating-Temperature Range (TA)
Package Type D (SBDIP) . . . . . . . . . . . . . . . . . . -55oC to +125oC
Package Type E (PDIP) . . . . . . . . . . . . . . . . . . . . -40oC to +85oC
Thermal Resistance (Typical, Note 1)
θJA ( oC/W) θJC (oC/W)
PDIP Package . . . . . . . . . . . . . . . . . . .
50
N/A
SBDIP Package. . . . . . . . . . . . . . . . . .
55
15
Maximum Junction Temperature
Plastic Package . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . +150oC
Ceramic Package . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . +175oC
Maximum Storage Temperature Range (TSTG) . . .-65oC to +150oC
Maximum Lead Temperature (Soldering 10s):
At Distance 1/16 ±1/32 inch (1.59 ±0.79mm) . . . . . . . . . . +265oC
CAUTION: Stresses above those listed in “Absolute Maximum Ratings” may cause permanent damage to the device. This is a stress only rating and operation
of the device at these or any other conditions above those indicated in the operational sections of this specification is not implied.
NOTE:
1. θJA is measured with the component mounted on an evaluation PC board in free air.
Operating Conditions At TA = Full Package-Temperature Range. For maximum reliability, operating conditions should be selected so
that operation is always within the following ranges:
LIMITS
CDP6402
PARAMETER
MIN
MAX
MIN
MAX
UNITS
4
10.5
4
6.5
V
VSS
VDD
VSS
VDD
V
DC Operating Voltage Range
Input Voltage Range
CDP6402C
Static Electrical Specifications at TA = -40oC to +85oC, VDD ±10%, Except as noted
CONDITIONS
LIMITS
CDP6402
PARAMETER
Quiescent Device
Current
Output Low Drive
(Sink) Current
Output High Drive
(Source) Current
Output Voltage LowLevel (Note 2)
Output Voltage
High Level (Note 2)
Input Low Voltage
IDD
IOL
IOH
VOL
VOH
VIL
CDP6402C
VO
(V)
V IN
(V)
VDD
(V)
MIN
(NOTE 1)
TYP
MAX
MIN
(NOTE 1)
TYP
MAX
UNITS
-
0, 5
5
-
0.01
50
-
0.02
200
µA
-
0,10
10
-
1
200
-
-
-
µA
0.4
0,5
5
2
4
-
1.2
2.4
-
mA
0.5
0,10
10
5
7
-
-
-
-
mA
4.6
0, 5
5
-0.55
-1.1
-
-0.55
-1.1
-
mA
9.5
0,10
10
-1.3
-2.6
-
-
-
-
mA
-
0, 5
5
-
0
0.1
-
0
0.1
V
-
0, 10
10
-
0
0.1
-
-
-
V
-
0, 5
5
4.9
5
-
4.9
5
-
V
-
0, 10
10
9.9
10
-
-
-
-
V
0.5, 4.5
-
5
-
-
0.8
-
-
0.8
V
0.5, 9.5
-
10
-
-
0.2 VDD
-
-
-
V
5-76
CDP6402, CDP6402C
Static Electrical Specifications at TA = -40oC to +85oC, VDD ±10%, Except as noted (Continued)
CONDITIONS
LIMITS
CDP6402
VO
(V)
V IN
(V)
VDD
(V)
MIN
(NOTE 1)
TYP
MAX
MIN
(NOTE 1)
TYP
MAX
UNITS
0.5, 4.5
-
5
VDD-2
-
-
V DD-2
-
-
V
0.5, 9.5
-
10
7
-
-
-
-
-
V
Any
Input
0,5
5
-
±10-4
±1
-
-
±1
µA
0,10
10
-
±10-4
±2
-
-
-
µA
0, 5
0, 5
5
-
±10-4
±1
-
±10-4
±1
µA
0, 10
0,10
10
-
±10-4
±10
-
-
-
µA
-
0, 5
5
-
1.5
−
-
1.5
-
mA
-
0,10
10
-
10
−
-
-
-
mA
CIN
-
-
-
-
5
7.5
-
5
7.5
pF
COUT
-
-
-
-
10
15
-
10
15
pF
PARAMETER
Input High Voltage
Input Leakage
Current
Three-State Output
Leakage Current
Operating Current
(Note 3)
Input Capacitance
Output Capacitance
CDP6402C
VIH
IIN
IOUT
IDD1
NOTES:
1. Typical values are for TA = 25oC and nominal VDD
2. IOL = IOH = 1µA.
3. Operating current is measured at 200kHz or VDD = 5V and 400kHz for VDD = 10V, with open outputs (worst-case frequencies for
CDP1802A system operating at maximum speed of 3.2MHz).
5-77
CDP6402, CDP6402C
Description of Operation
Initialization and Controls
Receiver Operation
A positive pulse on the MASTER RESET (MR) input resets
the control, status, and receiver buffer registers, and sets the
serial output (TRO) High. Timing is generated from the clock
inputs RRC and TRC at a frequency equal to 16 times the
serial data bit rate. The RRC and TRC inputs may be driven
by a common clock, or may be driven independently by two
different clocks. The CONTROL REGISTER LOAD (CRL)
input is strobed to load control bits for PARITY INHIBIT (PI),
EVEN PARITY ENABLE (EPE), STOP BIT SELECTS (SBS),
and CHARACTER LENGTH SELECTS (CLS1 and CLS2).
These inputs may be hand wired to V SS or VDD with CRL to
VDD . When the initialization is completed, the UART is ready
for receiver and/or transmitter operations.
Data is received in serial form at the RRl input. When no
data is being received, RRI input must remain high. The data
is clocked through the RRC. The clock rate is 16 times the
data rate. Receiver timing is shown in Figure 4.
8 1/2 TO 9 1/2
CLOCK CYCLES
BEGINNING OF FIRST STOP BIT
DATA
RRI
RBRI-8, OE
DRR
DR
Transmitter Operation
FE, PE
The transmitter section accepts parallel data, formats it, and
transmits it in serial form (Figure 2) on the TRO terminal.
1, 1-1/2 OR
2 STOP BITS
5 - 8 DATA BITS
START
BIT
LSB
A
MSB
C
1/2 CLOCK
CYCLES
FIGURE 4. RECEIVER TIMING WAVEFORMS
†
PARITY
† IF ENABLED
B
FIGURE 2. SERIAL DATA FORMAT
Transmitter timing is shown in Figure 3. (A) Data is loaded
into the transmitter buffer register from the inputs TBR1
through TBR8 by a logic low on the TBRL input. Valid data
must be present at least tDT prior to, and tTD following, the
rising edge of TBRL. If words less than 8-bits are used, only
the least significant bits are used. The character is right justified into the least significant bit, TBR1. (B) The rising edge of
TBRL clears TBRE. 1/2 to 11/2 cycles later, depending on
when the TBRL pulse occurs with respect to TRC, data is
transferred to the transmitter register and TRE is cleared.
TBRE is set to a logic High one cycle after that.
Output data is clocked by TRC. The clock rate is 16 times
the data rate. (C) A second pulse on TBRL loads data into
the transmitter buffer register. Data transfer to the transmitter
register is delayed until transmission of the current character
is complete. (D) Data is automatically transferred to the
transmitter register and transmission of that character
begins.
(A) A low level on DRR clears the DR line. (B) During the first
stop bit data is transferred from the receiver register to the
RB Register. If the word is less than 8 bits, the unused most
significant bits will be a logic low. The output character is
right justified to the least significant bit RBR1. A logic high on
OE indicates overruns. An overrun occurs when DR has not
been cleared before the present character was transferred to
the RBR. (C) 1/2 clock cycle later DR is set to a logic high
and FE is evaluated. A logic high on FE indicates an invalid
stop bit was received. A logic high on PE indicates a parity
error.
Start Bit Detection
The receiver uses a 16X clock for timing (Figure 5). The start
bit could have occurred as much as one clock cycle before it
was detected, as indicated by the shaded portion. The center of the start bit is defined as clock count 7 1/2. If the
receiver clock is a symmetrical square wave, the center of
the start bit will be located within ±1/2 clock cycle ±1/32 bit or
±3.125%. The receiver begins searching for the next start bit
at 9 clocks into the first stop bit.
COUNT 7 1/2
DEFINED CENTER
OF START BIT
TBRL
CLOCK
TBRE
1-1/2 TO 2-1/2 CYCLES
1/2
CLOCK
1/2 TO 1-1/2 CYCLES
TRE
TRO
RRI
INPUT
1 TO 2 CYCLES DATA
A
B
C
D
END OF
LAST
STOP BIT
FIGURE 3. TRANSMITTER TIMING WAVEFORMS
5-78
A
START
7 1/2 CLOCK
CYCLES
8 1/2 CLOCK
CYCLES
FIGURE 5. START BIT TIMING WAVEFORMS
CDP6402, CDP6402C
TABLE 1. CONTROL WORD FUNCTION
CONTROL WORD
CLS2
CLS1
PI
EPE
SBS
DATA BITS
PARITY BIT
STOP BIT (S)
L
L
L
L
L
5
ODD
1
L
L
L
L
H
5
ODD
1.5
L
L
L
H
L
5
EVEN
1
L
L
L
H
H
5
EVEN
1.5
L
L
H
X
L
5
DISABLED
1
L
L
H
X
H
5
DISABLED
1.5
L
H
L
L
L
6
ODD
1
L
H
L
L
H
6
ODD
2
L
H
L
H
L
6
EVEN
1
L
H
L
H
H
6
EVEN
2
L
H
H
X
L
6
DISABLED
1
L
H
H
X
H
6
DISABLED
2
H
L
L
L
L
7
ODD
1
H
L
L
L
H
7
ODD
2
H
L
L
H
L
7
EVEN
1
H
L
L
H
H
7
EVEN
2
H
L
H
X
L
7
DISABLED
1
H
L
H
X
H
7
DISABLED
2
H
H
L
L
L
8
ODD
1
H
H
L
L
H
8
ODD
2
H
H
L
H
L
8
EVEN
1
H
H
L
H
H
8
EVEN
2
H
H
H
X
L
8
DISABLED
1
H
H
H
X
H
8
DISABLED
2
NOTE: X = Don’t Care
5-79
CDP6402, CDP6402C
TABLE 2. FUNCTION PIN DEFINITION
PIN
SYMBOL
DESCRIPTION
1
VDD
Positive Power Supply
2
N/C
No Connection
3
GND
Ground (VSS)
4
RRD
A high level on RECEIVER REGISTER DISABLE forces the receiver holding register ouputs RBR1-RBR8 to
a high impedance state.
5
RBR8
The contents of the RECEIVER BUFFER REGISTER appear on these three-state outputs. Word formats less
than 8 characters are right justified to RBR1.
6
RBR7
7
RBR6
8
RBR5
9
RBR4
10
RBR3
11
RBR2
12
RBR1
13
PE
A high level on PARITY ERROR indicates that the received parity does not match parity programmed by control bits. The output is active until parity matches on a succeeding character. When parity is inhibited, this output is low.
14
FE
A high level on FRAMING ERROR indicates the first stop bit was invalid. FE will stay active until the next valid
character’s stop bit is received.
15
OE
A high level on OVERRUN ERROR indicates the data received flag was not cleared before the last character
was transferred to the receiver buffer register. The Error is reset at the next character’s stop bit if DRR has
been performed (i.e., DRR; active low).
16
SFD
A high level on STATUS FLAGS DISABLE forces the outputs PE, FE, OE, DR, TBRE to a high impedance
state.
17
RRC
The RECEIVER REGISTER CLOCK is 16X the receiver data rate.
18
DRR
A low level on DATA RECEIVED RESET clears the data received output (DR), to a low level.
19
DR
A high level on DATA RECEIVED indicates a character has been received and transferred to the receiver buffer
register.
20
RRl
Serial data on RECEIVER REGISTER INPUT is clocked into the receiver register.
21
MR
A high level on MASTER RESET (MR) clears PE, FE, OE and DR, and sets TRE, TBRE, and TRO. TRE is
actually set on the first rising edge of TRC after MR goes high. MR should be strobed after power-up.
22
TBRE
A high level on TRANSMITTER BUFFER REGISTER EMPTY indicates the transmitter buffer register has
transferred its data to the transmitter register and is ready for new data.
23
TBRL
A low level on TRANSMITTER BUFFER REGISTER LOAD transfers data from inputs TBR1-TBR8 into the
transmitter buffer register. A low to high transition on TBRL requests data transfer to the transmitter register. If
the transmitter register is busy, transfer is automatically delayed so that the two characters are transmitted end
to end.
24
TRE
A high level on TRANSMITTER REGISTER EMPTY indicates completed transmission of a character including
stop bits.
See Pin 5 - RBR8
5-80
CDP6402, CDP6402C
TABLE 2. FUNCTION PIN DEFINITION (Continued)
PIN
SYMBOL
DESCRIPTION
25
TRO
Character data, start data and stop bits appear serially at the TRANSMITTER REGISTER OUTPUT.
26
TBR1
Character data is loaded into the TRANSMITTER BUFFER REGISTER via inputs TBR1-TBR8. For character
formats less than 8 bits, the TBR8, 7, and 6 Inputs are ignored corresponding to the programmed word length.
27
TBR2
28
TBR3
29
TBR4
30
TBR5
31
TBR6
32
TBR7
33
TBR8
34
CRL
35
PI†
36
SBS†
A high level on STOP BIT SELECT selects 1.5 stop bits for a 5 character format and 2 stop bits for other
lengths.
37
CLS2†
These inputs program the CHARACTER LENGTH SELECTED. (CLS1 low CLS2 low 5 bits) (CLS1 high CLS2
low 6 bits) (CLS1 low CLS2 high 7 bits) (CLS1 high CLS2 high 8 bits).
38
CLS1†
See Pin 37 - CLS2
39
EPE†
When PI is low, a high level on EVEN PARITY ENABLE generates and checks even parity. A low level selects
odd parity.
40
TRC
The TRANSMITTER REGISTER CLOCK is 16X the transmit data rate.
See Pin 26 - TBR1
A high level on CONTROL REGISTER LOAD loads the control register.
A high level on PARITY INHIBIT inhibits parity generation, parity checking and forces PE output low.
† See Table 1 (Control Word Function)
5-81
CDP6402, CDP6402C
Dynamic Electrical Specifications at TA = -40oC to +85oC, VDD ±5%, tR, tF = 20ns, VIH = 0.7 VDD , VIL = 0.3 VDD , CL = 100pF
LIMITS
CDP6402
(NOTE 1)
PARAMETER
CDP6402C
VDD
(V)
(NOTE 2)
TYP
(NOTE 3)
MAX
(NOTE 2)
TYP
(NOTE 3)
MAX
UNITS
5
50
150
50
150
ns
10
40
100
-
-
ns
5
20
50
20
50
ns
10
0
40
-
-
ns
5
40
60
40
60
ns
10
20
30
-
-
ns
5
130
200
130
200
ns
10
100
150
-
-
ns
5
130
200
130
200
ns
10
40
60
-
-
ns
5
80
150
80
150
ns
10
40
70
-
-
ns
5
80
150
80
150
ns
10
40
70
-
-
ns
5
200
400
200
400
ns
10
100
200
-
-
ns
SYSTEM TIMING (See Figure 6)
Minimum Pulse Width
CRL
tCRL
Minimum Setup Time
Control Word to CRL
tCWC
Minimum Hold Time
Control Word after CRL
tCCW
Propagation Delay Time
SFD High to SOD
tSFDH
SFD Low to SOD
tSFDL
RRD High to Receiver Register
High Impedance
tRRDH
RRD Low to Receiver Register
Active
tRRDL
Minimum Pulse Width
MR
NOTES:
1. All measurements are made at the 50% point of the transition except three-state measurements.
2. Typical values for TA = 25oC and nominal VDD.
3. Maximum limits of minimum characteristics are the values above which all devices function.
CONTROL INPUT WORD TIMING
CONTROL WORD INPUT
CONTROL WORD BYTE
tCWC
tCCW
CRL
tCRL
STATUS OUTPUT TIMING
90%
10%
STATUS OUTPUTS
70%
30%
tSFDH
tSFDL
SFD
RECEIVER REGISTER DISCONNECT TIMING
90%
10%
R BUS 7
R BUS 0
tRRDH
70%
30%
tRRDL
RRD
FIGURE 6. SYSTEM TIMING WAVEFORMS
5-82
CDP6402, CDP6402C
Dynamic Electrical Specifications at TA = -40oC to +85oC, VDD ±5%, tR, tF = 20ns, VIH = 0.7 VDD , VIL = 0.3 VDD , CL = 100pF
LIMITS
CDP6402
(NOTE 1)
PARAMETER
CDP6402C
VDD
(V)
(NOTE 2)
TYP
(NOTE 3)
MAX
(NOTE 2)
TYP
(NOTE 3)
MAX
UNITS
5
250
310
250
310
ns
10
125
155
-
-
ns
5
100
125
100
125
ns
10
75
100
-
-
ns
5
100
125
100
125
ns
10
75
100
-
-
ns
5
80
200
80
200
ns
10
40
100
-
-
ns
5
175
275
175
275
ns
10
90
150
-
-
ns
5
20
50
20
50
ns
10
0
40
-
-
ns
5
40
60
40
60
ns
10
20
30
-
-
ns
5
300
450
300
450
ns
10
150
225
-
-
ns
5
330
400
330
400
ns
10
100
150
-
-
ns
5
200
300
200
300
ns
10
100
150
-
-
ns
5
330
400
330
400
ns
10
100
150
-
-
ns
TRANSMITTER TIMING (See Figure 7)
Minimum Clock Period (TRC)
tCC
Minimum Pulse Width
Clock Low Level
Clock High Level
TBRL
tCL
tCH
tTHTH
Minimum Setup Time
TBRL to Clock
Data to TBRL
tTHC
tDT
Minimum Hold-Time
Data after TBRL
tTD
Propagation Delay Time
Clock to Data Start Bit
Clock to TBRE
TBRL to TBRE
Clock to TRE
tCD
tCT
tTTHR
tTTS
NOTES:
1. All measurements are made at the 50% point of the transition except three-state measurements.
2. Typical values for TA = 25oC and nominal VDD.
3. Maximum limits of minimum characteristics are the values above which all devices function.
5-83
CDP6402, CDP6402C
TRANSMITTER BUFFER
REGISTER LOADED
(NOTE 1)
TRANSMITTER SHIFT
REGISTER LOADED
(NOTE 2)
tCC
tCH
tCL
TRC
1
3
2
4
5
6
7
14
15
16
1
2
3
tTHC
TBRL
tTHTH
tCD
tCD
1ST DATA BIT
TRO
tTTHR
tCT
TBRE
tTTS
TRE
tDT
T BUS 0
T BUS 7
tTD
DATA
NOTES:
1. The holding register is loaded on the trailing edge of TBRL.
2. The transmitter shift register, if empty, is loaded on the first high-to-low transition of the clock which occurs at least 1/2 clock period + tTHC
after the trailing edge of TBRL and transmission of a start bit occurs 1/2 clock period + tCD later.
FIGURE 7. TRANSMITTER TIMING WAVEFORMS
CLOCK 7 1/2
SAMPLE
tCC
tCH
RRC
CLOCK 7 1/2 LOAD
HOLDING REGISTER
tCL
1
2
3
4
5
6
7
16
1
2
3
4
5
6
7
8
9
tDC
(NOTE 1)
RRI
START BIT PARITY
STOP BIT 1
tCDV
R BUS 0 -
DATA
R BUS 7
DR
tDDA
tCDA
DRR
tCOE
tDD
OE
(NOTE 2)
tCPE
PE
tCFE
FE
NOTES:
1. If a start bit occurs at a time less than tDC before a high-to-low transition of the clock, the start bit may not be recognized until the next
high-to-low transition of the clock. The start bit may be completely asynchronous with the clock.
2. If a pending DA has not been cleared by a read of the receiver holding register by the time a new word is loaded into the receiver holding
register, the OE signal will come true.
FIGURE 8. RECEIVER TIMING WAVEFORMS
5-84
CDP6402, CDP6402C
Dynamic Electrical Specifications at TA = -40oC to +85oC, VDD ±5%, tR, tF = 20ns, VIH = 0.7 VDD , VIL = 0.3 VDD , CL = 100pF
LIMITS
CDP6402
(NOTE 1)
PARAMETERS
CDP6402C
VDD
(V)
(NOTE 2)
TYP
(NOTE 3)
MAX
(NOTE 2)
TYP
(NOTE 3)
MAX
UNITS
5
250
310
250
310
ns
10
125
155
-
-
ns
5
100
125
100
125
ns
10
75
100
-
-
ns
5
100
125
100
125
ns
10
75
100
-
-
ns
5
50
75
50
75
ns
10
25
40
-
-
ns
5
100
150
100
150
ns
10
50
75
-
-
ns
5
150
250
150
250
ns
10
75
125
-
-
ns
5
275
400
275
400
ns
10
110
175
-
-
ns
5
275
400
275
400
ns
10
110
175
-
-
ns
5
275
400
275
400
ns
10
100
150
-
-
ns
5
240
375
240
375
ns
10
120
175
-
-
ns
5
200
300
200
300
ns
10
100
150
-
-
ns
RECEIVER TIMING (See Figure 8)
Minimum Clock Period (RRC)
tCC
Minimum Pulse Width
Clock Low Level
Clock High Level
Data Received Reset
tCL
tCH
tDD
Minimum Setup Time
Data Start Bit to Clock
tDC
Propagation Delay Time
Data Received Reset to
Data Received
Clock to Data Valid
Clock to DR
Clock to Overrun Error
Clock to Parity Error
Clock to Framing Error
tDDA
tCDV
tCDA
tCOE
tCPE
tCFE
NOTES:
1. All measurements are made at the 50% point of the transition except three-state measurements.
2. Typical values for TA = 25oC and nominal VDD.
3. Maximum limits of minimum characteristics are the values above which all devices function.
5-85
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