INTERSIL HD-6402

HD-6402
TM
CMOS Universal Asynchronous
Receiver Transmitter (UART)
March 1997
Features
Description
• 8.0MHz Operating Frequency (HD-6402B)
The HD-6402 is a CMOS UART for interfacing computers or
microprocessors to an asynchronous serial data channel.
The receiver converts serial start, data, parity and stop bits.
The transmitter converts parallel data into serial form and
automatically adds start, parity and stop bits. The data word
length can be 5, 6, 7 or 8 bits. Parity may be odd or even.
Parity checking and generation can be inhibited. The stop
bits may be one or two or one and one-half when transmitting 5-bit code.
• 2.0MHz Operating Frequency (HD-6402R)
• Low Power CMOS Design
• Programmable Word Length, Stop Bits and Parity
• Automatic Data Formatting and Status Generation
• Compatible with Industry Standard UARTs
• Single +5V Power Supply
The HD-6402 can be used in a wide range of applications
including modems, printers, peripherals and remote data
acquisition systems. Utilizing the Intersil advanced scaled
SAJI IV CMOS process permits operation clock frequencies
up to 8.0MHz (500K Baud). Power requirements, by comparison, are reduced from 300mW to 10mW. Status logic
increases flexibility and simplifies the user interface.
• CMOS/TTL Compatible Inputs
Ordering Information
PACKAGE
TEMPERATURE RANGE
2MHz = 125K BAUD
8MHz = 500K BAUD
PKG. NO.
Plastic DIP
-40oC to +85oC
CERDIP
-40oC to +85oC
HD1-6402R-9
HD1-6402B-9
F40.6
SMD#
-55oC to +125oC
5962-9052501MQA
5962-9052502MQA
F40.6
HD3-6402R-9
HD3-6402B-9
E40.6
Pinout
HD-6402 (PDIP, CERDIP)
TOP VIEW
VCC
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
1
File Number
2956.1
HD-6402
Functional Diagram
(32)
TBR8
(24) TRE
(33)
(30)
(31)
(28)
(29)
(26)
(27)
TBR1
TRANSMITTER BUFFER REGISTER
(22) TBRE †
PARITY
LOGIC
STOP
(23) TBRL
TRANSMITTER REGISTER
TRANSMITTER
TIMING AND
CONTROL
(40) TRC
START
MULTIPLEXER
(25) TRO
(38) CLS1
(37) CLS2
(34) CRL
(21) MR
(36) SBS
(16) SFD
(39) EPE
(35) PI
CONTROL
REGISTER
(20) RRI
(17) RRC
MULTIPLEXER
RECEIVER
TIMING AND
CONTROL
(18) DRR
RECEIVER REGISTER
PARITY
LOGIC
STOP
LOGIC
(19) DR †
START
LOGIC
RECEIVER BUFFER REGISTER
3-STATE
(16) SFD
(4) RRD
BUFFERS
† RBR8
† THESE OUTPUTS ARE
THREE-STATE
† OE
(15)
† FE
(14)
† PE
(13)
† RBR1
(5) (6) (7) (8) (9) (10) (11) (12)
Control Definition
CONTROL WORD
CHARACTER FORMAT
CLS 2
CLS 1
PI
EPE
SBS
START BIT
DATA BITS
PARITY BIT
0
0
0
0
0
1
5
ODD
1
0
0
0
0
1
1
5
ODD
1.5
0
0
0
1
0
1
5
EVEN
1
0
0
0
1
1
1
5
EVEN
1.5
0
0
1
X
0
1
5
NONE
1
0
0
1
X
1
1
5
NONE
1.5
0
1
0
0
0
1
6
ODD
1
0
1
0
0
1
1
6
ODD
2
0
1
0
1
0
1
6
EVEN
1
0
1
0
1
1
1
6
EVEN
2
0
1
1
X
0
1
6
NONE
1
0
1
1
x
1
1
6
NONE
2
1
0
0
0
0
1
7
ODD
1
1
0
0
0
1
1
7
ODD
2
1
0
0
1
0
1
7
EVEN
1
1
0
0
1
1
1
7
EVEN
2
1
0
1
X
0
1
7
NONE
1
1
0
1
x
1
1
7
NONE
2
1
1
0
0
0
1
8
ODD
1
1
1
0
0
1
1
8
ODD
2
1
1
0
1
0
1
8
EVEN
1
1
1
0
1
1
1
8
EVEN
2
1
1
1
X
0
1
8
NONE
1
1
1
1
x
1
1
8
NONE
2
2
STOP BITS
HD-6402
Pin Description
PIN TYPE SYMBOL
1
VCC †
2
NC
3
GND
Ground
RRD
A high level on RECEIVER REGISTER DISABLE
forces the receiver holding out-puts RBR1-RBR8
to high impedance state.
4
I
PIN TYPE SYMBOL
DESCRIPTION
Positive Voltage Supply
DESCRIPTION
24
O
TRE
A high level on TRANSMITTER REGISTER EMPTY indicates completed transmission of a character including stop bits.
25
O
TRO
Character data, start data and stop bits appear serially at the TRANSMITTER REGISTER OUTPUT.
26
I
TRB1
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 their programmed word length.
27
I
TBR2
See Pin 26-TBR1.
28
I
TBR3
See Pin 26-TBR1.
29
I
TBR4
See Pin 26-TBR1.
30
I
TBR5
See Pin 26-TBR1.
31
I
TBR6
See Pin 26-TBR1.
32
I
TBR7
See Pin 26-TBR1.
33
I
TBR8
See Pin 26-TBR1.
34
I
CRL
A high level on CONTROL REGISTER LOAD
loads the control register with the control word. The
control word is latched on the falling edge of CRL.
CRL may be tied high.
No Connection
5
O
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
O
RBR7
See Pin 5-RBR8
7
O
RBR6
See Pin 5-RBR8
8
O
RBR5
See Pin 5-RBR8
9
O
RBR4
See Pin 5-RBR8
10
O
RBR3
See Pin 5-RBR8
11
O
RBR2
See Pin 5-RBR8
12
O
RBR1
See Pin 5-RBR8
13
O
PE
A high level on PARITY ERROR indicates received
parity does not match parity programmed by control
bits. When parity is inhibited this output is low.
14
O
FE
A high level on FRAMING ERROR indicates the
first stop bit was invalid.
35
I
PI
A high level on PARITY INHIBIT inhibits parity generation, parity checking and forces PE output low.
15
O
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.
36
I
SBS
A high level on STOP BIT SELECT selects 1.5
stop bits for 5 character format and 2 stop bits for
other lengths.
37
I
CLS2
16
I
SFD
A high level on STATUS FLAGS DISABLE forces
the outputs PE, FE, OE, DR, TBRE to a high impedance state.
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.)
17
I
RRC
The Receiver register clock is 16X the receiver
data rate.
38
I
CLS1
See Pin 37-CLS2.
39
I
EPE
When PI is low, a high level on EVEN PARITY
ENABLE generates and checks even parity. A low
level selects odd parity.
40
I
TRC
The TRANSMITTER REGISTER CLOCK is 16X
the transmit data rate.
18
I
DRR
A low level on DATA RECEIVED RESET clears
the data received output DR to a low level.
19
O
DR
A high level on DATA RECEIVED indicates a
character has been received and transferred to
the receiver buffer register.
20
I
RRI
Serial data on RECEIVER REGISTER INPUT is
clocked into the receiver register.
21
I
MR
A high level on MASTER RESET clears PE, FE,
OE and DR to a low level and sets the transmitter
register empty (TRE) to a high level 18 clock cycles
after MR falling edge. MR does not clear the receiver buffer register. This input must be pulsed at least
once after power up. The HD-6402 must be master
reset after power up. The reset pulse should meet
VIH and tMR. Wait 18 clock cycles after the falling
edge of MR before beginning operation.
22
O
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
I
TBRL
A low level on TRANSMITTER BUFFER REGISTER LOAD transfers data from inputs TBR1TBR8 into the transmitter buffer register. A low to
high transition on TBRL initiates data transfer to
the transmitter register. If busy, transfer is automatically delayed so that the two characters are
transmitted end to end.
† A 0.1µF decoupling capacitor from the VCC pin to the GND is recommended.
3
HD-6402
1
39
40
36
38
35
2
5
34
37
6
33
3
7
4
8
9
10
11
12
13
14
15
16
17
18
19
20
HD-6402
32
31
30
29
28
27
26
25
24
23
22
21
Transmitter Operation
The rising edge of TBRL clears Transmitter Buffer Register
Empty (TBRE). 0 to 1 Clock cycles later, data is transferred
to the transmitter register, the Transmitter Register Empty
(TRE) pin goes to a low state, TBRE is set high and serial
data information is transmitted. The output data is clocked
by Transmitter Register Clock (TRC) at a clock rate 16 times
the data rate. A second low level pulse on TBRL loads data
into the Transmitter Buffer Register (C). Data transfer to the
transmitter register is delayed until transmission of the current data is complete (D). Data is automatically transferred to
the transmitter register and transmission of that character
begins one clock cycle later.
The transmitter section accepts parallel data, formats the data
and transmits the data in serial form on the Transmitter Register Output (TRO) terminal (See serial data format). Data is
loaded from the inputs TBR1-TBR8 into the Transmitter Buffer
Register by applying a logic low on the Transmitter Buffer
Register Load (TBRL) input (A). Valid data must be present at
least tset prior to and thold following the rising edge of TBRL. If
words less than 8 bits are used, only the least significant bits
are transmitted. The character is right justified, so the least
significant bit corresponds to TBR1 (B).
1
TBRL
TBRE
1/2 CLOCK
0 TO 1 CLOCK
TRE
DATA
TRO
A
B
C
END OF LAST STOP BIT
D
FIGURE 1. TRANSMITTER TIMING (NOT TO SCALE)
Receiver Operation
character is right justified to the least significant bit RBR1. A
logic high on Overrun Error (OE) indicates overruns. An
overrun occurs when DR has not been cleared before the
present character was transferred to the RBR. One clock
cycle later DR is reset to a logic high, and Framing Error
(FE) is evaluated (C). A logic high on FE indicates an invalid
stop bit was received, a framing error. A logic high on Parity
Error (PE) indicates a parity error.
Data is received in serial form at the Receiver Register Input
(RRI). When no data is being received, RRI must remain
high. The data is clocked through the Receiver Register
Clock (RRC). The clock rate is 16 times the data rate. A low
level on Data Received Reset (DRR) clears the Data
Receiver (DR) line (A). During the first stop bit data is transferred from the Receiver Register to the Receiver Buffer
Register (RBR) (B). If the word is less than 8 bits, the
unused most significant bits will be a logic low. The output
BEGINNING OF FIRST STOP BIT
RRI
7 1/2 CLOCK CYCLES
RBR1-8, OE, PE
DRR
DR
FE
1 CLOCK CYCLE
A
B
C
FIGURE 2. RECEIVER TIMING (NOT TO SCALE)
4
HD-6402
START BIT
1, 11/2 OR 2 STOP BITS
5-8 DATA BITS
LSB
MSB
†
PARITY
† IF ENABLED
FIGURE 3. SERIAL DATA FORMAT
Start Bit Detection
symmetrical square wave, the center of the start bit will be
located within ±1/2 clock cycle, ±1/32 bit or 3.125% giving a
receiver margin of 46.875%. The receiver begins searching
for the next start bit at the center of the first stop bit.
The receiver uses a 16X clock timing. The start bit could have
occurred as much as one clock cycle before it was detected,
as indicated by the shaded portion (A). The center of the start
bit is defined as clock count 7 1/2. If the receiver clock is a
CLOCK
COUNT 71/2 DEFINED
CENTER OF START BIT
START
A
RRI INPUT
71/2 CLOCK CYCLES
81/2 CLOCK CYCLES
FIGURE 4.
Interfacing with the HD-6402
RECEIVER
RB1
TRANSMITTER
TBR1
TBR8
TRO
RS232
DRIVER
RS232
RECEIVER
RRI
CONTROL
CONTROL
DIGITAL
SYSTEM
HD-6402
HD-6402
CONTROL
CONTROL
RB1
RB8
RRI
RS232
RECEIVER
RS232
DRIVER
TRO
TBR1
TBR8
TRANSMITTER
RB8
RECEIVER
FIGURE 5. TYPICAL SERIAL DATA LINK
5
DIGITAL
SYSTEM
HD-6402
Absolute Maximum Ratings
Thermal Information
Supply Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . +8.0V
Input, Output or I/O Voltage Applied. . . . . GND -0.5V to VCC +0.5V
Storage Temperature Range . . . . . . . . . . . . . . . . . -65oC to +150oC
Junction Temperature. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . +175oC
Lead Temperature (Soldering 10s). . . . . . . . . . . . . . . . . . . . +300oC
ESD Classification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Class 1
Typical Derating Factor . . . . . . . . . . . 1mA/MHz Increase in ICCOP
Thermal Resistance (Typical)
θJA
θJC
CERDIP Package . . . . . . . . . . . . . . . . 50oC/W
12oC/W
PDIP Package . . . . . . . . . . . . . . . . . . . 50oC/W
N/A
Gate Count . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1643 Gates
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.
Operating Conditions
Operating Voltage Range . . . . . . . . . . . . . . . . . . . . . +4.5V to +5.5V
Operating Temperature Range
HD-6402R-9, HD6402B-9 . . . . . . . . . . . . . . . . . . .-40oC to +85oC
DC Electrical Specifications VCC = 5.0V ± 10%, TA = -40oC to +85oC (HD-6402R-9, HD-6402B-9)
LIMITS
SYMBOL
PARAMETER
MIN
MAX
UNITS
CONDITIONS
V IH
Logical ‘‘1’’ Input Voltage
2.0
-
V
VCC = 5.5V
VIL
Logical ‘‘0’’ Input Voltage
-
0.8
V
VCC = 4.5V
-1.0
1.0
µA
II
Input Leakage Current
VIN = GND or VCC, VCC = 5.5V
VOH
Logical ‘‘1’’ Output Voltage
3.0
VCC -0.4
-
V
IOH = -2.5mA, VCC = 4.5V
IOH = -100µA
VOL
Logical ‘‘0’’ Output Voltage
-
0.4
V
IOL = +2.5mA, VCC = 4.5V
IO
Output Leakage Current
-1.0
1.0
µA
VO = GND or VCC, VCC = 5.5V
ICCSB
Standby Supply Current
-
100
µA
VIN = GND or VCC; VCC = 5.5V,
Output Open
ICCOP
Operating Supply Current (See Note)
-
2.0
mA
VCC = 5.5V, Clock Freq. = 2MHz,
VIN = VCC or GND, Outputs Open
NOTE: Guaranteed, but not 100% tested
Capacitance TA = +25oC
LIMIT
PARAMETER
SYMBOL
CONDITIONS
TYPICAL
UNITS
CIN
Freq. = 1MHz, all measurements are referenced to device GND
25
pF
25
pF
Input Capacitance
Output Capacitance
COUT
AC Electrical Specifications VCC = 5.0V ± 10%, TA = -40oC to +85oC (HD-6402R-9, HD6402B-9)
LIMITS HD-6402R
SYMBOL
PARAMETER
LIMITS HD-6402B
MIN
MAX
MIN
MAX
UNITS
(1) fCLOCK
Clock Frequency
D.C.
2.0
D.C.
8.0
MHz
(2) tPW
Pulse Widths, CRL, DRR, TBRL
150
-
75
-
ns
(3) tMR
Pulse Width MR
150
-
150
-
ns
(4) tSET
Input Data Setup Time
50
-
20
-
ns
(5) tHOLD
Input Data Hold Time
60
-
20
-
ns
(6) tEN
Output Enable Time
-
160
-
35
ns
6
CONDITIONS
CL = 50pF
See Switching Waveform
HD-6402
Switching Waveforms
CLS1, CLS2, SBS, PI, EPE
TBR1 - TBR8
VALID DATA
SFD
RRD
VALID DATA
TBRL
STATUS OR
RBR1 - RBR8
CRL
(4)
tSET
tPW
(2)
tHOLD
(5)
(4)
tSET
tHOLD
(5)
tEN
(6)
tPW
(2)
FIGURE 6. DATA INPUT CYCLE
FIGURE 7. CONTROL REGISTER LOAD
CYCLE
FIGURE 8. STATUS FLAG OUTPUT
ENABLE TIME OR DATA OUTPUT ENABLE TIME
A.C. Testing Input, Output Waveform
INPUT
OUTPUT
VIH + 20% VIH
VOH
1.5V
1.5V
VIL - 50% VIL
VOL
FIGURE 9.
NOTE: A.C. Testing: All input signals must switch between V IL - 50% VIL and V IH + 20% VIH. Input rise and fall times are driven at 1ns/V.
Test Circuit
OUT
CL
(SEE NOTE)
FIGURE 10.
NOTE: Includes stray and jig capacitance, CL = 50pF.
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Intersil Corporation’s quality certifications can be viewed at www.intersil.com/design/quality
Intersil products are sold by description only. Intersil Corporation reserves the right to make changes in circuit design, software and/or specifications at any time without
notice. Accordingly, the reader is cautioned to verify that data sheets are current before placing orders. Information furnished by Intersil is believed to be accurate and
reliable. However, no responsibility is assumed by Intersil or its subsidiaries for its use; nor for any infringements 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 Intersil or its subsidiaries.
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