TL16C552A, TL16C552AM
DUAL ASYNCHRONOUS COMMUNICATIONS ELEMENT
WITH FIFO
SLLS189D – NOVEMBER 1994 – REVISED JANUARY 1999
Terminal Functions (Continued)
TERMINAL
NO.
I/O
DESCRIPTION
NAME
FN
PN
SOUT0,
SOUT1
26, 10
39, 23
O
Serial data outputs. SOUT0 and SOUT1 are the serial data outputs from the ACE transmitter circuitry.
A mark is a high state and a space is a low state. Each SOUT is held in the mark condition when the
transmitter is disabled (RESET is asserted low), the transmitter register is empty, or when in the loop
mode.
STB
TRI
55
2
74
12
I/O Line printer strobe. STB provides communication between the TL16C552A and the printer. When STB
is active (low), it provides the printer with a signal to latch the data currently on the parallel port. STB
has an internal pullup resistor to V
of approximately 10 kΩ.
DD
I
3-state output control input. TRI controls the 3-state control of all I/O and output terminals. When TRI
is asserted, all I/Os and outputs are in the high-impedance state, allowing board level testers to drive
theoutputswithoutoverdriving internalbuffers. TRIislevelsensitiveandispulleddownwithaninternal
resistor that is approximately 5 kΩ.
TXRDY0
TXRDY1
22, 42
35, 58
O
Transmitter ready. Two types of DMA signaling are available. Either can be selected using FCR3 when
operating in FIFO mode. Only DMA mode 0 is allowed when in TL16C450 mode. Single-transfer DMA
(a transfer is made between CPU bus cycles) is supported by mode 0. Multiple transfers that are made
continuously until the transmitter FIFO has been filled are supported by mode 1.
Mode 0. In FIFO mode (FCR0 = 1, FCR3 = 0) or in TL16C450 mode (FCR0 = 0) when there are no
characters in the transmitter holding register or transmitter FIFO, TXRDYx is active (low). Once
TXRDYx is activated (low), it goes inactive after the first character is loaded into the holding register
of the transmitter FIFO.
Mode 1. TXRDY goes active (low) in FIFO mode (FCR0 = 1) when FCR3 = 1 and there are no
characters in the transmitter FIFO. When the transmitter FIFO is completely full, TXRDY goes inactive
(high).
V
DD
23, 40,
64
6, 36,
56
Power supply. The V requirement is 5 V ±5%.
DD
†
absolute maximum ratings over operating free-air temperature range (unless otherwise noted)
Supply voltage range, V
(see Note 1) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . –0.5 V to V
+ 0.3 V
DD
DD
Input voltage range, V . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . –0.5 V to 7 V
I
Output voltage range, V
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . –0.5 V to V
+ 0.3 V
O
DD
Continuous total power dissipation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . See Dissipation Rating Table
Operating free-air temperature range, T : I suffix . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . –40°C to 85°C
A:
M suffix . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . –55°C to 125°C
Storage temperature range, T
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . –65°C to 150°C
stg
†
Stresses beyond those listed under “absolute maximum ratings” may cause permanent damage to the device. These are stress ratings only, and
functional operation of the device at these or any other conditions beyond those indicated under “recommended operating conditions” is not
implied. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability.
NOTE 1: All voltage levels are with respect to GND.
DISSIPATION RATING TABLE‡
§
T
≤ 25°C
DERATING FACTOR
T
= 70°C
T = 125°C
A
A
A
PACKAGE
POWER RATING
ABOVE T = 25°C
POWER RATING POWER RATING
A
FN
HV
1730 mW
19.2 mW/°C
13.5 mW/°C
865 mW
–
1689 mW
1081 mW
337 mW
‡
§
Power ratings assume a maximum junction temperature (T ) of 115°C for ’I’ and 150°C for ’M’ suffix devices.
J
Derating factor is the inverse of the junction-to-ambient thermal resistance, R
.
θJA
6
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