xr16c2850im Exar Corporation, xr16c2850im Datasheet - Page 50

• Manufacturer Part Number: xr16c2850im
• Description: Dual Uart With Tx And Rx Fifo Counters, 128 Bytes Of Fifos And Automatic Rs-485 Half Duplex Control
• Manufacturer: Exar Corporation

XR16C2850
2.97V TO 5.5V DUAL UART WITH 128-BYTE FIFOS
GENERAL DESCRIPTION .................................................................................................1
PIN DESCRIPTIONS .........................................................................................................3
1.0 PRODUCT DESCRIPTION .....................................................................................................................7
2.0 FUNCTIONAL DESCRIPTIONS .............................................................................................................8
3.0 UART INTERNAL REGISTERS ...........................................................................................................21
4.0 INTERNAL REGISTER DESCRIPTIONS .............................................................................................23
A
F
ORDERING INFORMATION
EATURES
PPLICATIONS
2.1 CPU INTERFACE .............................................................................................................................................. 8
2.2 DEVICE RESET ................................................................................................................................................ 8
2.3 DEVICE IDENTIFICATION AND REVISION ..................................................................................................... 8
2.4 CHANNEL A AND B SELECTION .................................................................................................................... 8
2.5 CHANNEL A AND B INTERNAL REGISTERS ................................................................................................ 9
2.6 DMA MODE ....................................................................................................................................................... 9
2.7 INTA AND INTB OUPUTS .............................................................................................................................. 10
2.8 CRYSTAL OSCILLATOR OR EXTERNAL CLOCK INPUT ........................................................................... 10
2.9 PROGRAMMABLE BAUD RATE GENERATOR ........................................................................................... 11
2.10 TRANSMITTER ............................................................................................................................................. 12
2.11 RECEIVER .................................................................................................................................................... 14
2.12 AUTO RTS (HARDWARE) FLOW CONTROL ............................................................................................. 15
2.13
2.14 AUTO CTS FLOW CONTROL ...................................................................................................................... 16
2.15 AUTO XON/XOFF (SOFTWARE) FLOW CONTROL ................................................................................... 17
2.16
2.17
2.18 INFRARED MODE ........................................................................................................................................ 18
2.19
2.20
4.1 RECEIVE HOLDING REGISTER (RHR) - READ- ONLY ............................................................................... 23
4.2 TRANSMIT HOLDING REGISTER (THR) - WRITE-ONLY ............................................................................ 23
4.3 INTERRUPT ENABLE REGISTER (IER) - READ/WRITE .............................................................................. 23
F
F
F
T
T
T
T
F
F
F
T
F
F
F
F
F
T
F
F
T
T
IGURE
IGURE
IGURE
ABLE
ABLE
ABLE
ABLE
IGURE
IGURE
IGURE
ABLE
IGURE
IGURE
IGURE
IGURE
IGURE
ABLE
IGURE
IGURE
ABLE
ABLE
2.10.1 TRANSMIT HOLDING REGISTER (THR) - WRITE ONLY ....................................................................................... 12
2.10.2 TRANSMITTER OPERATION IN NON-FIFO MODE ................................................................................................ 12
2.10.3 TRANSMITTER OPERATION IN FIFO MODE ......................................................................................................... 13
2.11.1 RECEIVE HOLDING REGISTER (RHR) - READ-ONLY .......................................................................................... 14
4.3.1 IER VERSUS RECEIVE FIFO INTERRUPT MODE OPERATION ............................................................................. 23
4.3.2 IER VERSUS RECEIVE/TRANSMIT FIFO POLLED MODE OPERATION ................................................................ 24
AUTO RTS HYSTERESIS ............................................................................................................................ 15
SPECIAL CHARACTER DETECT ............................................................................................................... 17
AUTO RS485 HALF-DUPLEX CONTROL .................................................................................................. 17
SLEEP MODE WITH AUTO WAKE-UP ....................................................................................................... 19
INTERNAL LOOPBACK .............................................................................................................................. 20
1: C
2: T
3: INTA
4: INTA
5: T
6: A
7:
8:
1. XR16C2850 B
2. P
3.
4. T
5. E
6. B
7. T
8. T
9. R
10. R
11. A
12. I
13. I
.....................................................................................................................................................1
ABLE
YPICAL DATA RATES WITH A
UART CHANNEL A AND B UART INTERNAL REGISTERS...................................................................................... 21
INTERNAL REGISTERS DESCRIPTION. S
UTO
HANNEL
XR16C2850 D
YPICAL OSCILLATOR CONNECTIONS
RANSMITTER
RANSMITTER
IN
XTERNAL
AUD
ECEIVER
NFRARED
NTERNAL
................................................................................................................................................1
UTO
ECEIVER
O
AND
AND
X
2TXRDY#
UT
R
ON
RTS
ATE
A
A
INTB P
INTB P
/X
O
SSIGNMENT
C
AND
L
OFF
T
O
G
PERATION IN NON
LOCK
OOP
AND
RANSMIT
PERATION IN
ENERATOR AND
O
O
.................................................................................................................................2
LOCK
B S
PERATION IN NON
PERATION IN
(S
ATA
AND
INS
IN
CTS F
B
C
OFTWARE
ACK IN
ELECT
O
ONNECTION FOR
D
B
O
PERATION
RXRDY# O
..................................................................................................................................................... 2
US
D
IAGRAM
PERATION FOR
ATA
LOW
I
NTERCONNECTIONS
............................................................................................................................................... 9
C
FIFO
14.7456 MH
) F
HANNELS
E
FIFO
C
-FIFO M
P
NCODING AND
......................................................................................................................................... 1
TABLE OF CONTENTS
LOW
ONTROL
RESCALER
F
AND
OR
-FIFO M
UTPUTS IN
AND
............................................................................................................................... 10
C
R
E
A
ONTROL
A
T
XTENDED
ODE
ECEIVER
UTO
RANSMITTER
O
F
AND
Z CRYSTAL OR EXTERNAL CLOCK
LOW
PERATION
..................................................................................................................... 11
ODE
.................................................................................................................... 14
RTS F
R
B .............................................................................................................. 20
FIFO
ECEIVE
HADED BITS ARE ENABLED WHEN
................................................................................................................. 8
............................................................................................................... 17
C
.............................................................................................................. 13
............................................................................................................. 10
ONTROL
D
ATA
LOW
AND
....................................................................................................... 16
...................................................................................................... 10
I
D
R
ATA
DMA M
C
ATE
M
ONTROL
ODE
D
.......................................................................................... 11
ECODING
..................................................................................... 13
ODE
M
................................................................................ 9
ODE
.......................................................................... 18
....................................................................... 15
...................................................................... 12
EFR B
IT
-4=1......................................... 22
xr
REV. 2.1.3