XR16V794_08 EXAR [Exar Corporation], XR16V794_08 Datasheet
![no-image](/images/no-image-200.jpg)
XR16V794_08
Related parts for XR16V794_08
XR16V794_08 Summary of contents
Page 1
HIGH PERFORMANCE 2.25V TO 3.6V QUAD UART WITH FRACTIONAL JULY 2008 GENERAL DESCRIPTION 1 The XR16V794 (794 2.25V to 3.6V octal Universal Asynchronous Receiver and Transmitter (UART) with 5V tolerant serial (modem) inputs. The highly integrated device is ...
Page 2
XR16V794 HIGH PERFORMANCE 2.25V TO 3.6V QUAD UART WITH FRACTIONAL BAUD RATE IGURE THE EVICE 48 47 XTAL2 XTAL1 GND VCC TX0 DTR0# RTS0# RI0# CD0# DSR0# CTS0# RX0 INT# CS# A0 ...
Page 3
HIGH PERFORMANCE 2.25V TO 3.6V QUAD UART WITH FRACTIONAL BAUD RATE REV. 1.0.1 PIN DESCRIPTIONS AME IN YPE DATA BUS INTERFACE A7-A0 6-1,64,63 I D7:D0 18-11 IO IOR IOW (R/W#) CS# 62 ...
Page 4
XR16V794 HIGH PERFORMANCE 2.25V TO 3.6V QUAD UART WITH FRACTIONAL BAUD RATE AME IN YPE DTR0 DSR0 CD0 RI0 TX1 48 O RX1 41 I RTS1 ...
Page 5
HIGH PERFORMANCE 2.25V TO 3.6V QUAD UART WITH FRACTIONAL BAUD RATE REV. 1.0 AME IN YPE TX3 28 O RX3 21 I RTS3 CTS3 DTR3 DSR3 CD3# 24 ...
Page 6
XR16V794 HIGH PERFORMANCE 2.25V TO 3.6V QUAD UART WITH FRACTIONAL BAUD RATE 1.0 DESCRIPTION The XR16V794 (794) integrates the functions of 4 enhanced 16550 UARTs, a general purpose 16-bit timer/ counter and an on-chip oscillator. The device configuration registers include ...
Page 7
HIGH PERFORMANCE 2.25V TO 3.6V QUAD UART WITH FRACTIONAL BAUD RATE REV. 1.0.1 2.4 INT# Ouput The INT# interrupt output changes according to the operating mode and enhanced features setup. and 3 summarize the operating behavior for the transmitter and ...
Page 8
XR16V794 HIGH PERFORMANCE 2.25V TO 3.6V QUAD UART WITH FRACTIONAL BAUD RATE 2.6 Programmable Baud Rate Generator with Fractional Divisor Each UART has its own Baud Rate Generator (BRG) with a prescaler for the transmitter and receiver. The prescaler is ...
Page 9
HIGH PERFORMANCE 2.25V TO 3.6V QUAD UART WITH FRACTIONAL BAUD RATE REV. 1.0 ABLE YPICAL DATA RATES WITH A Required D IVISOR FOR Output Data 16x Clock O Rate (Decimal) 400 3750 2400 625 4800 312.5 9600 ...
Page 10
XR16V794 HIGH PERFORMANCE 2.25V TO 3.6V QUAD UART WITH FRACTIONAL BAUD RATE 2.7.1 Transmit Holding Register (THR) - Write Only The transmit holding register is an 8-bit register providing a data interface to the host processor. The host writes transmit ...
Page 11
HIGH PERFORMANCE 2.25V TO 3.6V QUAD UART WITH FRACTIONAL BAUD RATE REV. 1.0.1 2.8 Receiver The receiver section contains an 8-bit Receive Shift Register (RSR) and 64 bytes of FIFO which includes a byte-wide Receive Holding Register (RHR). The RSR ...
Page 12
XR16V794 HIGH PERFORMANCE 2.25V TO 3.6V QUAD UART WITH FRACTIONAL BAUD RATE IGURE ECEIVER PERATION IN 16X or 8X Clock Receive Data Shift Register (RSR) 64 bytes by 11-bit wide FIFO Receive Data FIFO Receive Receive ...
Page 13
HIGH PERFORMANCE 2.25V TO 3.6V QUAD UART WITH FRACTIONAL BAUD RATE REV. 1.0.1 2.10 Auto RTS/DTR Hardware Flow Control Operation Automatic RTS/DTR flow control is used to prevent data overrun to the local receiver FIFO. The RTS#/DTR# output pin is ...
Page 14
XR16V794 HIGH PERFORMANCE 2.25V TO 3.6V QUAD UART WITH FRACTIONAL BAUD RATE RTS/DTR CTS/DSR F IGURE UTO AND Local UART UARTA Receiver FIFO Trigger Reached Auto RTS Trigger Level Transmitter Auto CTS Monitor Assert RTS# to Begin ...
Page 15
HIGH PERFORMANCE 2.25V TO 3.6V QUAD UART WITH FRACTIONAL BAUD RATE REV. 1.0.1 In the event that the receive buffer is overfilling and flow control needs to be executed, the 794 automatically sends an Xoff message (when enabled) via the ...
Page 16
XR16V794 HIGH PERFORMANCE 2.25V TO 3.6V QUAD UART WITH FRACTIONAL BAUD RATE The infrared encoder sends out a 3/ bit wide HIGH-pulse for each “0” bit in the transmit data stream. This signal encoding reduces the on-time of ...
Page 17
HIGH PERFORMANCE 2.25V TO 3.6V QUAD UART WITH FRACTIONAL BAUD RATE REV. 1.0.1 2.15 Sleep Mode with Auto Wake-Up The 794 supports low voltage system designs, hence, a sleep mode is included to reduce its power consumption when the chip ...
Page 18
XR16V794 HIGH PERFORMANCE 2.25V TO 3.6V QUAD UART WITH FRACTIONAL BAUD RATE 2.16 Internal Loopback Each UART channel provides an internal loopback capability for system diagnostic purposes. The internal loopback mode is enabled by setting MCR register bit-4 to logic ...
Page 19
HIGH PERFORMANCE 2.25V TO 3.6V QUAD UART WITH FRACTIONAL BAUD RATE REV. 1.0.1 F 12. T XR16V794 R IGURE HE EGISTERS 8-bit Data Bus Interface 3.1 DEVICE CONFIGURATION REGISTER SET The device configuration registers are directly accessible from the bus. ...
Page 20
XR16V794 HIGH PERFORMANCE 2.25V TO 3.6V QUAD UART WITH FRACTIONAL BAUD RATE Bit 7 DDRESS EAD R EGISTER [A7:A0] W RITE 0x80 R INT Source Reserved Reserved Reserved Reserved 0x81 R INT 1 UART 2 bit ...
Page 21
HIGH PERFORMANCE 2.25V TO 3.6V QUAD UART WITH FRACTIONAL BAUD RATE REV. 1.0.1 3.1.1.1 INT0 Channel Interrupt Indicator: Bit-7 Rsvd Rsvd Rsvd Rsvd 3.1.1.2 INT1, INT2 and INT3 Interrupt Source Locator INT3, INT2 and INT1 provide a 24-bit (3 bits ...
Page 22
XR16V794 HIGH PERFORMANCE 2.25V TO 3.6V QUAD UART WITH FRACTIONAL BAUD RATE 3.1.2 General Purpose 16-bit Timer/Counter [TIMERMSB, TIMELSB, TIMER, TIMECNTL XX-XX-00-00) X The 794 includes a 16-bit general purpose timer/counter. Its clock source may be selected from ...
Page 23
HIGH PERFORMANCE 2.25V TO 3.6V QUAD UART WITH FRACTIONAL BAUD RATE REV. 1.0.1 TIMER OPERATION The following paragraphs describe the operation of the 16-bit Timer/Counter. The following conventions will be used in this discussion: ’N’ is the 16-bit value programmed ...
Page 24
XR16V794 HIGH PERFORMANCE 2.25V TO 3.6V QUAD UART WITH FRACTIONAL BAUD RATE 3.1.3 8XMODE [7:0] (default 0x00) Each bit selects 8X or 16X sampling rate for that UART channel, bit-0 is channel 0. Logic 0 (default) selects normal 16X sampling ...
Page 25
HIGH PERFORMANCE 2.25V TO 3.6V QUAD UART WITH FRACTIONAL BAUD RATE REV. 1.0.1 3.1.7.1 DVID [7:0] (default 0x48) Device identification for the type of UART. The Device ID for the V794 is 0x44. Examples: XR16V794 = 0x44 XR16L784 = 0x24 ...
Page 26
XR16V794 HIGH PERFORMANCE 2.25V TO 3.6V QUAD UART WITH FRACTIONAL BAUD RATE 3.2 UART CHANNEL CONFIGURATION REGISTERS The first 8 registers are 16550 compatible with EXAR enhanced feature registers located on the upper 8 addresses. The 4 sets of UART ...
Page 27
HIGH PERFORMANCE 2.25V TO 3.6V QUAD UART WITH FRACTIONAL BAUD RATE REV. 1.0.1 T 12: UART CHANNEL CONFIGURATION REGISTERS DESCRIPTION. ABLE DDRESS EG EAD A3- AME RITE ...
Page 28
XR16V794 HIGH PERFORMANCE 2.25V TO 3.6V QUAD UART WITH FRACTIONAL BAUD RATE T 12: UART CHANNEL CONFIGURATION REGISTERS DESCRIPTION. ABLE DDRESS EG EAD A3- AME RITE TXTRG ...
Page 29
HIGH PERFORMANCE 2.25V TO 3.6V QUAD UART WITH FRACTIONAL BAUD RATE REV. 1.0.1 IER[7]: CTS# Input Interrupt Enable (requires EFR bit-4=1) • Logic 0 = Disable the CTS# interrupt (default). • Logic 1 = Enable the CTS# interrupt. The UART ...
Page 30
XR16V794 HIGH PERFORMANCE 2.25V TO 3.6V QUAD UART WITH FRACTIONAL BAUD RATE 4.4 Interrupt Status Register (ISR) - Read Only The UART provides multiple levels of prioritized interrupts to minimize external software interaction. The Interrupt Status Register (ISR) provides the ...
Page 31
HIGH PERFORMANCE 2.25V TO 3.6V QUAD UART WITH FRACTIONAL BAUD RATE REV. 1.0.1 ISR[7:6]: FIFO Enable Status These bits are set to a logic 0 when the FIFOs are disabled. They are set to a logic 1 when the FIFOs ...
Page 32
XR16V794 HIGH PERFORMANCE 2.25V TO 3.6V QUAD UART WITH FRACTIONAL BAUD RATE T 14: T ABLE RANSMIT AND T FCTR FCTR FCR RIGGER ABLE Table ...
Page 33
HIGH PERFORMANCE 2.25V TO 3.6V QUAD UART WITH FRACTIONAL BAUD RATE REV. 1.0.1 LCR[5]: TX and RX Parity Select If the parity bit is enabled, LCR BIT-5 selects the forced parity format. • LCR BIT-5 = logic 0, parity is ...
Page 34
XR16V794 HIGH PERFORMANCE 2.25V TO 3.6V QUAD UART WITH FRACTIONAL BAUD RATE 4.7 Modem Control Register (MCR) - Read/Write The MCR register is used for controlling the modem interface signals or general purpose inputs/outputs. MCR[7]: Clock Prescaler Select (requires EFR ...
Page 35
HIGH PERFORMANCE 2.25V TO 3.6V QUAD UART WITH FRACTIONAL BAUD RATE REV. 1.0.1 MCR[1]: RTS# Output The RTS# pin may be used for automatic hardware flow control by enabled by EFR bit-6 and MCR bit-2=0. If the modem interface is ...
Page 36
XR16V794 HIGH PERFORMANCE 2.25V TO 3.6V QUAD UART WITH FRACTIONAL BAUD RATE LSR[1]: Receiver Overrun Flag • Logic overrun error (default). • Logic 1 = Overrun error. A data overrun error condition occurred in the receive shift ...
Page 37
HIGH PERFORMANCE 2.25V TO 3.6V QUAD UART WITH FRACTIONAL BAUD RATE REV. 1.0.1 MSR[1]: Delta DSR# Input Flag • Logic change on DSR# input (default). • Logic 1 = The DSR# input has changed state since the ...
Page 38
XR16V794 HIGH PERFORMANCE 2.25V TO 3.6V QUAD UART WITH FRACTIONAL BAUD RATE MSR [3]: Transmitter Disable This bit can be used to disable the transmitter by halting the Transmit Shift Register (TSR). When this bit is set to a ’1’, ...
Page 39
HIGH PERFORMANCE 2.25V TO 3.6V QUAD UART WITH FRACTIONAL BAUD RATE REV. 1.0 ABLE ELECTABLE FCTR B -3 FCTR ...
Page 40
XR16V794 HIGH PERFORMANCE 2.25V TO 3.6V QUAD UART WITH FRACTIONAL BAUD RATE EFR[5]: Special Character Detect Enable • Logic 0 = Special Character Detect Disabled (default). • Logic 1 = Special Character Detect Enabled. The UART compares each incoming receive ...
Page 41
HIGH PERFORMANCE 2.25V TO 3.6V QUAD UART WITH FRACTIONAL BAUD RATE REV. 1.0.1 4.14 TXCNT[7:0]: Transmit FIFO Level Counter - Read Only Transmit FIFO level byte count from 0x00 (zero) to 0x40 (64). This 8-bit register gives an indication of ...
Page 42
XR16V794 HIGH PERFORMANCE 2.25V TO 3.6V QUAD UART WITH FRACTIONAL BAUD RATE REGISTERS RESET STATE DLL Bits 7-0 = 0x01 DLM Bits 7-0 = 0x00 DLD Bits 7-0 = 0x00 RHR Bits 7-0 = 0xXX THR Bits 7-0 = 0xXX ...
Page 43
HIGH PERFORMANCE 2.25V TO 3.6V QUAD UART WITH FRACTIONAL BAUD RATE REV. 1.0.1 ABSOLUTE MAXIMUM RATINGS Power Supply Range Voltage at Any Pin Operating Temperature Storage Temperature Package Dissipation Thermal Resistance (10x10x1.4mm 64-LQFP) ELECTRICAL CHARACTERISTICS DC ELECTRICAL CHARACTERISTICS o o ...
Page 44
XR16V794 HIGH PERFORMANCE 2.25V TO 3.6V QUAD UART WITH FRACTIONAL BAUD RATE AC ELECTRICAL CHARACTERISTICS TA (-40 to +85 C for industrial grade package), Vcc is 2.25V to 3.6V Load where ...
Page 45
HIGH PERFORMANCE 2.25V TO 3.6V QUAD UART WITH FRACTIONAL BAUD RATE REV. 1.0.1 AC ELECTRICAL CHARACTERISTICS TA (-40 to +85 C for industrial grade package), Vcc is 2.25V to 3.6V Load ...
Page 46
XR16V794 HIGH PERFORMANCE 2.25V TO 3.6V QUAD UART WITH FRACTIONAL BAUD RATE F 16 IGURE ODE NTEL ATA A0-A7 Valid Address T AS CS# IOR# T RDV D0-D7 A0-A7 Valid Address T AS CS# IOW# ...
Page 47
HIGH PERFORMANCE 2.25V TO 3.6V QUAD UART WITH FRACTIONAL BAUD RATE REV. 1.0 IGURE ODE OTOROLA A0-A7 T ADS CS# T RWS R/W# T RDA D0-D7 A0-A7 T ADS CS# T RWS R/W# ...
Page 48
XR16V794 HIGH PERFORMANCE 2.25V TO 3.6V QUAD UART WITH FRACTIONAL BAUD RATE F 18 IGURE ODEM NPUT UTPUT IOW # Active RTS# Change of state DTR# CD# CTS# DSR# INT IOR# RI ...
Page 49
HIGH PERFORMANCE 2.25V TO 3.6V QUAD UART WITH FRACTIONAL BAUD RATE REV. 1.0 IGURE RANSMIT NTERRUPT IMING ...
Page 50
XR16V794 HIGH PERFORMANCE 2.25V TO 3.6V QUAD UART WITH FRACTIONAL BAUD RATE PACKAGE DIMENSIONS 64 LEAD LOW-PROFILE QUAD FLAT PACK ( 1.4 mm LQFP) A Seating Plane Note: The control dimension is the millimeter column SYMBOL A ...
Page 51
HIGH PERFORMANCE 2.25V TO 3.6V QUAD UART WITH FRACTIONAL BAUD RATE REV. 1.0.1 REVISION HISTORY R D EVISION ATE A1.0.0 June 2005 Advanced Datasheet. A1.0.1 March 2006 Updated the 1.4mm-thick Quad Flat Pack package description from "TQFP" to "LQFP" to ...
Page 52
XR16V794 HIGH PERFORMANCE 2.25V TO 3.6V QUAD UART WITH FRACTIONAL BAUD RATE GENERAL DESCRIPTION ................................................................................................ 1 A ............................................................................................................................................... 1 PPLICATIONS F .................................................................................................................................................... 1 EATURES ............................................................................................................................................................. 1 IGURE LOCK IAGRAM .................................................................................................................................................. 2 ...
Page 53
HIGH PERFORMANCE 2.25V TO 3.6V QUAD UART WITH FRACTIONAL BAUD RATE REV. 1.0.1 3.1.2.2 TIMER [7:0] R ESERVED 3.1.2.3 TIMERCNTL [7:0] R EGISTER T 10: TIMER C C ABLE ONTROL OMMANDS TIMER OPERATION ................................................................................................................................................ ............................................................................................................................................. ...