DAN-121 Datasheet, PDF (2/3 Pages) Exar Corporation – EXAR’S XR68C92/192 COMPARED

DATA COMMUNICATIONS APPLICATION NOTE
DAN121
1.4 SUMMARY OF DIFFERENCES
In the table below, some differences between the XR68C92/192 and SCC68692 are summarized.
TABLE 1: DIFFERENCES BETWEEN EXAR’S XR68C92/192 WITH PHILIPS’S SCC68692
DIFFERENCES
Data Bus Standard
Power Supply Operation
Max Operating Current
Max Frequency on XTAL1
Max Data Rate
Operating Temperature Range
Package
TX FIFO Size
RX FIFO Size
TX FIFO Trigger Levels
RX FIFO Trigger Levels
XR68C92/192
Motorola
3.3 and 5 V
3 mA @ 3.3 V
6 mA @ 5 V
24 MHz
1 Mbps
Commercial and Industrial
44-TQFP, 44-PLCC,
40-PDIP
8 (XR68C92)
16 (XR68C192)
8 (XR68C92)
16 (XR68C192)
8, 4, 6, 1 (XR68C92)
16, 8, 12, 1(XR68C192)
1, 3, 6, 8 (XR68C92)
1, 6, 12, 16 (XR68C192)
SCC68692
Motorola
5 V only
10 mA @ 5 V
4 MHz
125 Kbps
Commercial and Industrial
44-PLCC, 40-PDIP,
40-CDIP
1
3
1
1, 3
1.5 REPLACING THE SCC68692 WITH THE XR68C92/192
You can directly replace the Philips SCC68692 with Exar’s XR68C92/192 without any hardware changes if us-
ing either the 44-PLCC or 40-PDIP packages. Hardware changes will be necessary to upgrade to the smaller
44-TQFP package.
Since the XR68C92/192 has a larger Transmit and Receive FIFO, the software will need to be updated to fully
utilize the features of the XR68C92/192. The XR68C92/192 allows the hardware designer to choose either a 5
or 3.3 V power supply instead of being limited to a 5 V power supply only. Also, the XR68C92/192 has a lower
power consumption than the SCC68692.
The XR68C92/192 can accept up to a 24 MHz frequency on XTAL1 whereas the SCC68692 can only accept
up to a 4 MHz frequency. The maximum data transfer rate for the XR68C92/192 is 1 Mbps compared to only
125 Kbps for the SCC68692.
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