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Oxford Semiconductor Ltd.
25 Milton Park, Abingdon, Oxon, OX14 4SH, UK
Tel: +44 (0)1235 824900
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Oxford Semiconductor 2001 .
DATA SHEET .
CONFIDENTIAL .
F
EATURES
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 Microwire
TM
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
D
ESCRIPTION
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 industry-
standard 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
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.
the
OXCF950
DATA SHEET