STARTECH
An
Company
ST16C2552
Printed December 17, 1996
DUAL ASYNCHRONOUS RECEIVER/TRANSMITTER WITH FIFOs
DESCRIPTION
The ST16C2552 is a dual asynchronous receiver and
transmitter with 16 byte transmit and receive FIFOs.
Independent programmable baud rate generators are
provided to select transmit and receive clock rates
from 50Hz to 1.5 MHz for each UART.
The on board status registers of the ST16C2552
provide the error conditions, type and status of the
transfer operation being performed. Complete MO-
DEM control capability and a processor interrupt
system that may be software tailored to the user’s
requirements are included. The ST16C2552 provides
internal loop-back capability for on board diagnostic
testing.
Signalling for DMA transfers is done through two pins
per channel ( TXRDY*, RXRDY* ). The RXRDY*
function is multiplexed on one pin with the OP2* and
BAUDOUT functions. CPU can select these functions
through the Alternate Function Register.
The ST16C2552 is fabricated in an advanced 0.6m
CMOS process to achieve low power and high speed
requirements.
PLCC Package
TXRDYA*
DSRA*
41
CTSA*
40
39
38
37
36
35
CDA*
42
VCC
44
RIA*
43
D4
D3
D2
D1
3
6
5
4
2
D0
D5
D6
D7
A0
XTAL1
GND
XTAL2
A1
A2
CHSEL
INTB
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
1
RXA
TXA
DTRA*
RTSA*
MFA*
INTA
VCC
TXRDYB*
RIB*
CDB*
DSRB*
ST16C2552CJ44
34
33
32
31
30
29
CS*
MFB*
IOW*
IOR*
RESET
DTRB*
DSRA*
RXB
GND
RTSB*
TXB
FEATURES
TXRDYA*
·
Pin to pin and functional compatible to National
NS16C552
·
16 byte transmit FIFO
·
16 byte receive FIFO with error flags
·
Modem control signals (CTS*, RTS*, DSR*, DTR*,
RI*, CD*)
·
Programmable character lengths (5, 6, 7, 8) bits
·
Even, odd, or no parity bit generation and detection
·
Status report register
·
TTL compatible inputs, outputs
·
Independent transmit and receive control
·
Software compatible with INS8250, NS16C550
·
460.8 kHz transmit/receive operation with 7.372
MHz crystal or external clock source
CTSA*
38
CDA*
VCC
RIA*
CTSB*
37
36
35
34
33
32
31
N.C.
D4
D3
D2
D1
45
48
47
46
44
D0
43
42
41
40
N.C.
D5
D6
D7
A0
XTAL1
GND
XTAL2
A1
A2
CHSEL
INTB
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
39
RXA
TXA
DTRA*
RTSA*
MFA*
INTA
VCC
TXRDYB*
RIB*
CDB*
DSRB*
N.C.
ST16C2552CQ48
30
29
28
27
26
25
CS*
MFB*
IOW*
RTSB*
IOR*
DTRB*
Part number
Package
Operating temperature
ST16C2552CJ44
ST16C2552IJ44
PLCC
PLCC
0° C to + 70° C
-40° C to + 85° C
Rev. 2.0
3-135
RESET
CTSB*
N.C.
RXB
GND
TXB
ORDERING INFORMATION
EXAR [ EXAR CORPORATION ]
