XR17V258IV-F Exar Corporation, XR17V258IV-F Datasheet - Page 20

• Manufacturer Part Number: XR17V258IV-F
• Description: IC UART PCI BUS OCTAL 144LQFP
• Manufacturer: Exar Corporation
• Type: Octal UARTr

Specifications of XR17V258IV-F

• Number Of Channels: 8
• Package / Case: 144-LQFP
• Features: *
• Fifo's: 64 Byte
• Protocol: RS485
• Voltage - Supply: 3.3V, 5V
• With Auto Flow Control: Yes
• With Irda Encoder/decoder: Yes
• With False Start Bit Detection: Yes
• With Modem Control: Yes
• Mounting Type: Surface Mount
• Data Rate: 8 Mbps
• Supply Voltage (max): 3.6 V
• Supply Voltage (min): 3 V
• Supply Current: 4 mA
• Maximum Operating Temperature: + 85 C
• Minimum Operating Temperature: - 45 C
• Mounting Style: SMD/SMT
• Operating Supply Voltage: 3 V to 3.6 V
• No. Of Channels: 8
• Uart Features: Tx/Rx FIFO Counters
• Supply Voltage Range: 3V To 3.6V
• Operating Temperature Range: -40°C To +85°C
• Digital Ic Case Style: LQFP
• No. Of Pins: 144
• Rohs Compliant: Yes
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant, Lead free / RoHS Compliant

XR17V258
66MHZ PCI BUS OCTAL UART WITH POWER MANAGEMENT SUPPORT
The XR17V258 has a general purpose 16-bit timer/counter. The crystal/clock at the XTAL1 input or an external
clock at the TMRCK input pin can be selected as the clock source for the timer/counter. The timer can be set to
be a single-shot for a one-time event or re-triggerable for a periodic signal. An interrupt may be generated
when the timer times out and will show up as a Channel 0 interrupt (see
configuration registers [TIMERCNTL, TIMER, TIMELSB, TIMERMSB]. The TIMERCNTL register provides the
Timer commands such as start/stop, as shown in
optionally routed to the MPIO[0] pin. The block diagram of the Timer/Counter circuit is shown below:
TIMERMSB [31:24] and TIMERLSB [23:16]
The concatentaion of the 8-bit registers TIMERMSB and TIMERLSB forms a 16-bit value which decides the
time-out period of the Timer, per the following equation:
The least-significant bit of the timer is being bit [0] of the TIMERLSB with most-significant-bit being bit [7] in
TIMERMSB. Notice that these registers do not hold the current counter value when read. Default value is zero
(timer disabled) upon powerup and reset. The ’Reset Timer’ command does not have any effect on this
register.
TIMER [15:8] Reserved
1.6.2
Bit-15 Bit-14 Bit-13 Bit-12 Bit-11 Bit-10
F
IGURE
0
General Purpose 16-bit Timer/Counter [TIMERMSB, TIMELSB, TIMER, TIMECNTL] (
COM M ANDS
TIM ERCNTL
X
TIM ERM SB and TIM ERLSB
XX-XX-00-00)
6. T
Timer output frequency = Timer input clock / 16-bit Timer value
OSC. CLOCK
IMER
TIMERMSB Register
(16-bit Value)
TM RCK
/C
Clock Select
Single shot/Re-triggerable
Start/Stop
Tim er Interrupt Enable/ Disable
Route/De-route to M PIO[0]
OUNTER CIRCUIT
1
0
16-Bit Timer/Counter Programmable Registers
Bit-9 Bit-8
Tim er/Counter
Table 10
16-Bit
20
Bit-7
below. The time-out output of the Timer can also be
Tim er Interrupt
M PIOLVL[0]
Output
Tim er
Bit-6
1
0
Bit-5
TIMERLSB Register
Table 8
Bit-4
M PIO[0]
1
0
). It is controlled through 4
Bit-3
Tim er Interrupt
No Interrupt
Bit-2
Bit-1 Bit-0
REV. 1.0.2
DEFAULT