Part Numbers May Be Marked With "IMP" or "Ei."
Semiconductor, Inc.
Ei82C684
Ei68C684
QUAD UART
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Programmable internal clock:X1/CLK or
X1/CLK divided by 2
Buffered system clock output pin
Stand-by mode to reduce operating power
Advanced CMOS low power technology
FEATURES
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Full duplex, four channel asynchronous
receiver and transmitter
Quadruple-buffered receiver and transmitter
Internal bit rate generator with 23 industry
standard bit rates operating from either of
two standard crystal clocks
Independent bit rate selection for each
receiver and transmitter
Maximum bit rate: 1 x clock - 2 Mb/sec., 16
x clock- 250 Kb/sec.
Normal, auto-echo, local loop-back and
remote loop-back modes
Multi-function 16-bit counter/timer
Programmable interrupt daisy chain
Up to 32 I/O pins (depending on package
and version)
Change of state detectors on inputs
Multidrop mode compatible with 8051 nine-
bit mode
Stop bits programmable in 1/16-bit increments
Pin selectable 88xxx/68xxx interface
Debounced reset pin (20 nsec. min)
On-chip oscillator for crystal
DESCRIPTION
The Epic Ei68C684/Ei88C684 Quad Universal
Asynchronous Receiver and Transmitter (QUART) is a
data communication device that provides four fully
independent full duplex asynchronous communication
channels in a single package. The QUART is designed
for use in microprocessor based systems and may be
used in a polled or interrupt driven environment.
Two basic versions of the QUART are pin selectable
with SEL pin and each is optimized for use with various
microprocessor families: the Ei88C684 for 8080/5,
8086/88, Z80, Z8000, 68XX and 65XX family based
systems., and the 68C681 for 68000 family based sys-
tems.and the Ei68C684 for 68000family based systems
A programmable mode of the Ei88C684 versions pro-
vides an interrupt daisy chain for use in Z80 and Z8000
based systems. The bus interfaces are however gener-
al enough to allow interfacing with other microprocessors
and microcontrollers. The Ei88C684 and Ei68C684 are
high integrated versions of Epic Semiconductor’s
Ei88C681 and Ei66C681 DUART’s respectively, and are
function compatible with those devices.
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9
8
7
6
5
4
3
2
1
68
67
66
65
64
63
62
61
OP4
X2
X1/CLK
RXDB
TXDB
OP3
OP2
SEL
VCC0
VCC1
RESET
OP1(RTSB•)
OP0(RTSA•)
TXDA
RXDA
IP7
IP6
RXDD
TXDD
(IEO)
IACK•
INTR•
CLKBUF+OP11
GND
GND
OP10
OP9(RTSD•)
OP8(RTSC•)
TXDC
RXDC
IP15
IP14
IP13
IP12
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
OP5
OP6
OP7
D0
D1
D2
D3
D4
D5
D6
D7
WR•
CE•
OP15
OP14
OP13
OP12
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
Ei82C684
60
59
58
57
56
55
54
53
52
51
50
49
48
47
46
45
44
IP5
IP4•
RD•
IP3
IP2
IP1(CTSB•)
IP0(CTSA•)
A1
A2
A3
A4
A5
IP8(CTSC•)
IP9(CTSD•)
IP10
IP11
IEI
X2
X1/CLK
RXDB
TXDB
OP3
SEL
VCC
RESET
OP1(RTSB)
OP0(RTSA)
TXDA
1
D0
D1
D2
D3
D4
D5
D6
D7
R/WN
CEN
RXDD
RXDA
RDN
IP1(CTSB)
IP0(CTSA)
A1
A2
A3
A4
A5
IP8(CTSC)
IP9(CTSD)
Ei82C684
68-PIN PLCC
15
TXDD
(IEO)
IACKN
INTRN
OP11
GND
OP9(RTSD)
OP8(RTSB)
TXDC
RXDC
IEI
44-PIN PLCC
IMP [ IMP, INC ]
