xr17l152im Exar Corporation, xr17l152im Datasheet - Page 11
xr17l152im
Manufacturer Part Number
xr17l152im
Description
3.3v Pci Bus Dual Uart
Manufacturer
Exar Corporation
Datasheet
1.XR17L152IM.pdf
(55 pages)
XR17L152
3.3V PCI BUS DUAL UART
REV. 1.1.0
The XR17L152 has a 32-bit wide register [INT0, INT1, INT2 and INT3] to provide interrupt information and
supports two interrupt schemes. The first scheme is a 2-bit indicator in INT0 register representing the 2
channels with the first 3 bits representing each channel from 0 to 1. This permits the interrupt routine to quickly
vector and serve that UART channel and determine the source(s) in each individual routines. INT0 bit-0
represents the interrupt status for UART channel 0 when its transmitter, receiver, line status, or modem port
status requires service. INT0 bit-1 provides interrupt status for channel 1 and bits 2 to 7 are reserved and
remain at a logic 0.
The second scheme provides detail about the source of the interrupts for each UART channel. All the interrupts
are encoded into a 3-bit code per channel. This 3-bit code represents 7 interrupts corresponding to individual
UART’s transmitter, receiver, line status, modem port status. INT1 and INT2 registers provide the 6-bit interrupt
status for both channels. Bits 8, 9 and 10 represents channel 0 and bits 11,12 and 13 represents channel 1.
Bits 14 to 31 are reserved and remain at logic zero. Both channels interrupt status are available with a single
DWORD read operation. This feature allows the host to quickly vector and serve the interrupts, reducing
service interval, hence, reducing host bandwidth requirements.
GLOBAL INTERRUPT REGISTER (DWORD)
Upon power-up or reset, all bits are a logic 0. A special interrupt condition is generated by the L152 upon
awakening from sleep after both channels were put to sleep mode earlier.
register and its make up.
INT0 [7:0] Channel Interrupt Indicator.
Each bit gives an indication of the channel that has requested for service. Bit-0 represents channel 0 and bit-1
indicates channel 1. Logic one indicates the channel N [1:0] has requested for service. Bits 2 to 7 are reserved
and remain at logic zero The interrupt bit clears after reading the appropriate register of the interrupting
channel register, see Interrupt Clearing section.
1.2.1
0x088-08B
0x08C-08F
0x080
0x084-087
0x090-093
A
DDRESS
A
[A7:A0]
Ox091
Ox092
Ox093
DDRESS
INT3 [31:24]
-
083
The Interrupt Status Register
T
ABLE
T
ANCILLARY1 (read/write)
ANCILLARY2 (read-only)
INTERRUPT (read-only)
ABLE
TIMER (read/write)
MPIO (read/write)
4: D
MPIOSEL
R
MPIOINV
3: D
MPIO3T
R
EGISTER
EGISTER
EVICE
EVICE
INT2 [23:16]
C
C
ONFIGURATION
ONFIGURATION
Read/Write MPIO input polarity select
Read/Write MPIO select
Read/Write MPIO output control
B
TIMERMSB
YTE
MPIOSEL
MPIOINT
SLEEP
[default 0x00-00-00-00]
INT3
R
3 [31:24]
R
EGISTERS SHOWN IN
R
11
EGISTERS SHOWN IN
EAD
/W
RITE
B
INT1 [15:8]
YTE
TIMERLSB
C
MPIOINV
RESET
REGB
OMMENT
INT2
2 [23:16]
DWORD
BYTE
Figure 4
B
ALIGNMENT
YTE
(reserved)
(reserved)
MPIO3T
ALIGNMENT
TIMER
REGA
DVID
INT1
shows the 4-byte interrupt
1 [15:8]
DISCONTINUED
Bits 7-0 = 0xFF
INT0 [7:0]
Bits 7-0 = 0x00
Bits 7-0 = 0x00
áç
áç
áç
áç
R
ESET
B
TIMERCNTL
YTE
8XMODE
MPIOLVL
DREV
S
INT0
TATE
0 [7:0]