XR17V358 Datasheet, PDF (9/68 Pages) Exar Corporation – HIGH PERFORMANCE OCTAL PCI EXPRESS UART

REV. P1.0.2
FUNCTIONAL DESCRIPTION
PRELIMINARY
XR17V358
HIGH PERFORMANCE OCTAL PCI EXPRESS UART
The XR17V358 (V358) integrates the functions of eight independent enhanced 16550 UARTs, a general
purpose 16-bit timer/counter, and 16 multi-purpose I/Os (MPIOs). Each UART channel has its own 16550
UART compatible configuration register set for individual channel control, status and data transfer. The device
configuration registers include a set of four consecutive interrupt source registers that provides interrupt status
for all eight UARTs, timer/counter, MPIOs and a sleep wake-up indicator. Additionally, each UART channel has
256-byte of transmit and receive FIFOs, automatic RTS/CTS or DTR/DSR hardware flow control, automatic
XON/XOFF, special character flow control, programmable transmit and receive FIFO trigger levels, infrared
encoder/decoder (IrDA ver. 1.1), and a programmable fractional baud rate generator with a prescaler of divide
by 1 or 4, and a data rate up to 25 Mbps with the 4X sampling rate.
PCIE INTERFACE AND DATA TRANSFERS
This is the host interface and it meets the PCIe base specifications revision 2.0 Gen 1. The V358 also supports
data read/write burst operations so the 256-byte TX or RX FIFO can be loaded or unloaded in a single
transaction greatly increasing the overall system performance.
LOCAL BUS CONFIGURATION SPACE REGISTERS
A set of local bus configuration space register is provided. These registers provide the PCI vendor ID, device
ID, sub-vendor ID, product model number, resources and capabilities which is collected by the host during the
auto configuration phase that follows immediately after a power up or system reset/reboot. After the host has
sorted out all devices on the bus, it defines and download the operating conditions to the cards. One of the
definitions is the base address loaded into the Base Address Register (BAR) where the card will be operating
in the PCI local bus memory space. All this is described in more detail in “Section 1.1, PCI LOCAL BUS
CONFIGURATION SPACE REGISTERS” on page 10.
EEPROM INTERFACE
An external 93C46 EEPROM is used to store words of information such as PCI Vendor ID, PCI Device ID,
Class Code, etc. Details of this information can be found in “Section 1.2, EEPROM Interface” on page 14.
This information is only used with the plug-and-play auto configuration of the PCI local bus. These data provide
automatic hardware installation onto the PCI bus. The EEPROM interface consists of 4 signals, EEDI, EEDO,
EECS, and EECK. The EEPROM is not needed when auto configuration is not required in the application.
However, if your design requires non-volatile memory for other purpose, it is possible to store and retrieve data
on the EEPROM through a special PCI device configuration register. See application note DAN112 for its
programming details.
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