OXCF950

Features:

·  Single full-duplex asynchronous channel
·  128-byte deep transmitter / receiver FIFO
·  Fully software compatible with industry standard 16C550 type UARTs
·  Readable FIFO levels
·  System clock up to 60MHz at 5V, 50 MHz at 3.3V
·  Flexible clock prescaler from 1 to 31.875
·  9-bit data framing as well as 5,6,7 and 8
·  Detection of bad data in the receiver FIFO
·  Automated in-band flow control using programmable Xon/Xoff characters
·  Transmitter and receiver can be disabled
·  Low power CMOS
·  3.3V / 5V operation
·  Programmable by external MicrowireTM EEPROM (EEPROM programmed via Oxford Semiconductor utilities).
·  Extremely low power consumption by use of asynchronous UART core and power down (sleep) modes
·  Ultra small 48 pin TQFP package.
·  Supports all UART types 450 up to 950 (fully programmable)
·  CF+ Compliant (Revision 1.4).
·  16-bit PC Card Compliant (PCMCIA Revision 7.1)
·  8 bit Local Bus interface included for PCMCIA applications
·  2 Multi-purpose I/O pins which can be configured as interrupt inputs


Pinout




Specifications

Symbol	Parameter	Min	Max	Units
VDD	DC supply voltage	3	5.25	V
TO	Operating Temperature range	0	70

Description

The OXCF950 is a low cost asynchronous 16-bit PC card (henceforth referred to as PCMCIA) or Compact Flash (henceforth referred to as CF) UART (and Local Bus) device. Local Bus Selection is performed by use of a MODE pin. Note that Local Bus mode uses indirect addressing, which is only supported by PCMCIA.

The 3.3V / 5V technology has been selected to allow the device to be used in both high and low voltage environments, as stated in the PCMCIA specification. Note that when the OXCF950 is operating at 3.3V, its I/O is not 5V tolerant.

The EEPROM interface allows the programming of the Attribute Memory, UART and Local Configuration Registers during power up or hard/soft reset. This allows different card manufacturers to modify the information contained in the Attribute memory or UART/registers as required, for example PC-Card ID value.

A number of power-down modes are included to keep power consumption to a minimum. Such features include clock division (fully programmable) and sleep modes when a function of the OXCF950 is not being used.

The OXCF950 contains a single-channel ultra-high performance UART offering data rates up to 15Mbps (at 5V) and 128-deep transmitter and receiver FIFOs. Deep FIFOs reduce CPU overhead and allow utilisation of higher data rates.

It is software compatible with the widely used industrystandard 16C550 type devices and compatibles, as well as other OX16C95x family devices.

In addition to increased performance and FIFO size, the OXCF950 also provides enhanced features including improved flow control. Automated software flow control using Xon/Xoff and automated hardware flow control using CTS#/RTS# and DSR#/DTR# prevent FIFO over-run. Flow control and interrupt thresholds are fully programmable and readable, enabling programmers to fine- tune the performance of their system. FIFO levels are readable to facilitate fast driver applications.

The addition of software reset enables recovery from unforeseen error conditions allowing drivers to restart gracefully. The OXCF950 supports 9-bit data frames used in multi-drop industrial protocols. It also offers multiple external clock options for isochronous applications, e.g. ISDN, xDSL.

The OXCF950 also incorporates a bridge to an 8 bit Local Bus in Local Bus Mode. It allows card developers to expand the capabilities of their products by adding peripherals to this bus. In addition, two user IO pins are included to enhance external device control. These IO pins can also be configured as interrupt inputs.