xr20m1172 Exar Corporation, xr20m1172 Datasheet - Page 55

• Manufacturer Part Number: xr20m1172
• Description: Two Channel I2c/spi Uart With 64-byte Fifo
• Manufacturer: Exar Corporation

REV. 1.0.0
GENERAL DESCRIPTION................................................................................................ 1
PIN DESCRIPTIONS ........................................................................................................ 3
1.0 PRODUCT DESCRIPTION ...................................................................................................................... 6
2.0 FUNCTIONAL DESCRIPTIONS .............................................................................................................. 7
3.0 UART INTERNAL REGISTERS............................................................................................................. 24
A
F
ORDERING INFORMATION
EATURES
PPLICATIONS
2.1 CPU INTERFACE ................................................................................................................................................ 7
2.2 DEVICE RESET ................................................................................................................................................. 11
2.3 INTERNAL REGISTERS.................................................................................................................................... 11
2.4 IRQ# OUTPUT ................................................................................................................................................... 11
2.5 CRYSTAL OSCILLATOR OR EXTERNAL CLOCK INPUT.............................................................................. 12
2.6 PROGRAMMABLE BAUD RATE GENERATOR WITH FRACTIONAL DIVISOR ........................................... 12
2.7 TRANSMITTER.................................................................................................................................................. 14
2.8 RECEIVER ......................................................................................................................................................... 16
2.9 AUTO RTS (HARDWARE) FLOW CONTROL .................................................................................................. 17
2.10 AUTO RTS HALT AND RESUME .................................................................................................................. 17
2.11 AUTO CTS FLOW CONTROL........................................................................................................................ 17
2.12 AUTO XON/XOFF (SOFTWARE) FLOW CONTROL...................................................................................... 19
2.13 SPECIAL CHARACTER DETECT.................................................................................................................. 19
2.14 AUTO RS485 HALF-DUPLEX CONTROL ..................................................................................................... 19
2.15 INFRARED MODE ........................................................................................................................................... 21
2.16 SLEEP MODE WITH AUTO WAKE-UP ......................................................................................................... 22
2.17 INTERNAL LOOPBACK................................................................................................................................. 23
F
F
F
F
F
F
T
T
T
F
F
F
T
T
F
F
F
T
F
F
F
F
F
F
F
T
IGURE
IGURE
IGURE
IGURE
IGURE
IGURE
ABLE
ABLE
ABLE
IGURE
IGURE
IGURE
ABLE
ABLE
IGURE
IGURE
IGURE
ABLE
IGURE
IGURE
IGURE
IGURE
IGURE
IGURE
IGURE
ABLE
2.1.1 I2C-BUS INTERFACE ..................................................................................................................................................... 7
2.1.2 SPI BUS INTERFACE ................................................................................................................................................... 10
2.7.1 TRANSMIT HOLDING REGISTER (THR) - WRITE ONLY........................................................................................... 15
2.7.2 TRANSMITTER OPERATION IN NON-FIFO MODE .................................................................................................... 15
2.7.3 TRANSMITTER OPERATION IN FIFO MODE ............................................................................................................. 15
2.8.1 RECEIVE HOLDING REGISTER (RHR) - READ-ONLY .............................................................................................. 16
2.14.1 NORMAL MULTIDROP MODE ................................................................................................................................... 19
2.14.2 AUTO ADDRESS DETECTION .................................................................................................................................. 20
1: XR20M1172 I2C A
2: I2C S
3: SPI F
4: IRQ# P
5: IRQ# P
6: T
7: UART INTERNAL REGISTER ADDRESSES .............................................................................................................. 24
1. XR20M1172 B
2. P
3. I2C S
4. M
5. M
6. I2C D
7. SPI W
8. SPI R
9. SPI FIFO W
10. SPI FIFO R
11. T
12. B
13. T
14. T
15. R
16. R
17. A
18. I
19. I
2.1.1.1 I2C-
.................................................................................................................................................... 1
YPICAL DATA RATES WITH A
IN
ASTER
ASTER
NFRARED
NTERNAL
YPICAL OSCILLATOR CONNECTIONS
RANSMITTER
RANSMITTER
AUD
UTO
ECEIVER
ECEIVER
.............................................................................................................................................. 1
O
UB
IRST
UT
ATA
EAD
TART AND
IN
IN
RITE
-A
R
RTS
W
R
A
O
O
ATE
B
DDRESS
BUS
F
EADS
..................................................................................................................................................................... 10
SSIGNMENT
PERATION FOR
PERATION
RITES
.................................................................................................................................................................... 10
YTE
L
ORMATS
T
O
O
RITE
OOP
AND
RANSMIT
EAD
G
PERATION IN NON
PERATION IN
A
LOCK
ENERATOR
............................................................................................................................... 2
F
O
O
F
DDRESSING
S
ORMAT
........................................................................................................................................................... 10
T
PERATION IN NON
PERATION IN
CTS F
.......................................................................................................................................................... 11
B
ROM
(R
TOP
DDRESS
O
ACK
........................................................................................................................................................ 8
EGISTER
S
D
F
..................................................................................................................................................... 2
D
LAVE
IAGRAM
OR
C
S
................................................................................................................................................. 23
ATA
LAVE
LOW
ONDITIONS
................................................................................................................................................ 10
T
R
............................................................................................................................................. 13
FIFO
M
RANSMITTER
24 MH
ECEIVER
(M1172) .............................................................................................................................. 7
............................................................................................................................................ 9
E
AP
C
A
NCODING AND
(M1172) ........................................................................................................................... 7
FIFO
........................................................................................................................................ 1
-FIFO M
ONTROL
DDRESS
TABLE OF CONTENTS
AND
...................................................................................................................................... 9
Z CRYSTAL OR EXTERNAL CLOCK AT
-FIFO M
................................................................................................................................. 7
AND
............................................................................................................................. 12
............................................................................................................................. 11
A
UTO
) .......................................................................................................................... 9
ODE
O
........................................................................................................................ 11
F
PERATION
LOW
ODE
RTS F
.................................................................................................................. 16
R
ECEIVE
C
............................................................................................................ 15
ONTROL
LOW
....................................................................................................... 18
I
TWO CHANNEL I2C/SPI UART WITH 64-BYTE FIFO
D
ATA
C
ONTROL
M
D
ODE
ECODING
................................................................................... 15
M
ODE
16X S
.......................................................................... 21
....................................................................... 17
AMPLING
................................................... 14
XR20M1172