DAN-124 Datasheet, PDF (1/3 Pages) Exar Corporation – EXAR’S XR88C92/192 COMPARED

DATA COMMUNICATIONS APPLICATION NOTE
DAN124
June 2002
EXAR’S XR88C92/192 COMPARED WITH PHILIPS’S SC26C92
Author: PY
1.0 INTRODUCTION
This application note describes the major difference between Exar’s XR88C92/192 with Philips’s SC26C92.
These devices are very similar, with a few hardware, firmware-related and bus timing differences.
1.1 HARDWARE DIFFERENCES
• The Philips SC26C92 and Exar XR88C92/192 are both available in three footprints: 44-pin PLCC, 44-pin
QFP and 40-pin DIP. The Exar and Philips DUARTs are pin-to-pin compatible in all three footprints.
• The Exar’s 44-pin TQFP package is the same size and has the same pitch as the Philips’ 44-pin QFP pack-
age. But they differ in the package thickness and the lead length. See the list below:
Thickness:
Lead Length, Lp:
Exar
1.4mm
0.45mm < Lp < 0.75mm
Philips
1.75mm
0.55mm < Lp < 0.95mm
1.2 FIRMWARE DIFFERENCES
All the internal registers in the SC26C92 and XR88C92/192 are identical with only one exception:
• Since the XR88C192 has a 16-byte FIFO as compared to a 8-byte FIFO in the SC26C92, the selectable
transmit and receive trigger levels are different.
1.3 BUS TIMING DIFFERENCES
• The XR88C92/192 is faster than the SC26C92. For example, the data access time (from -CS low to data
valid) during a read is a maximum of 32 ns for the XR88C92/192, whereas it is a maximum of 55 ns for the
SC26C92.
EXAR Corporation 48720 Kato Road, Fremont CA, 94538 • [phone] • FAX [phone] • www.exar.com • [e-mail]