SC16C554 Philips Semiconductors, SC16C554 Datasheet - Page 18

• Manufacturer Part Number: SC16C554
• Description: Quad UART with 16-byte FIFO and infrared (IrDA) encoder/decoder
• Manufacturer: Philips Semiconductors

Philips Semiconductors
9397 750 13132
Product data
6.10 Programmable baud rate generator
The SC16C554/554D supports high speed modem technologies that have increased
input data rates by employing data compression schemes. For example, a 33.6 kbit/s
modem that employs data compression may require a 115.2 kbit/s input data rate.
A 128.0 kbit/s ISDN modem that supports data compression may need an input
data rate of 460.8 kbit/s.
A single baud rate generator is provided for the transmitter and receiver, allowing
independent TX/RX channel control. The programmable Baud Rate Generator is
capable of accepting an input clock up to 80 MHz (for 3.3 V and 5 V operation), as
required for supporting a 5 Mbit/s data rate. The SC16C554/554D can be configured
for internal or external clock operation. For internal clock oscillator operation, an
industry standard microprocessor crystal (parallel resonant/22-33 pF load) is
connected externally between the XTAL1 and XTAL2 pins (see
Alternatively, an external clock can be connected to the XTAL1 pin to clock the
internal baud rate generator for standard or custom rates (see
Programming the Baud Rate Generator Registers DLM (MSB) and DLL (LSB)
provides a user capability for selecting the desired final baud rate.
Table 7:
Output baud rate
200
1200
2400
4800
9600
19.2 k
38.4 k
76.8 k
153.6 k
230.4 k
460.8 k
Fig 7. Crystal oscillator connection.
Baud rate generator programming table using a 7.3728 MHz clock
Quad UART with 16-byte FIFO and infrared (IrDA) encoder/decoder
Rev. 05 — 10 May 2004
1.8432 MHz
C1
47 pF
User
16 clock divisor
Decimal
2304
384
192
96
48
24
12
6
3
2
1
X1
C2
100 pF
HEX
900
180
C0
60
30
18
0C
06
03
02
01
SC16C554/554D
1.8432 MHz
C1
22 pF
DLM
program value
(HEX)
09
01
00
00
00
00
00
00
00
00
00
© Koninklijke Philips Electronics N.V. 2004. All rights reserved.
X1
1.5 k
Table
C2
47 pF
Figure
002aaa169
7).
DLL
program value
(HEX)
00
80
C0
60
30
18
0C
06
03
02
01
7).
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