DAN-139 Datasheet, PDF (2/5 Pages) Exar Corporation – EXAR’S XR16L580 COMPARED

DATA COMMUNICATIONS APPLICATION NOTE
DAN139
TABLE 1: LEGACY SIGNALS IN THE INUDSTRY STANDARD 16550, 48-TQFP PACKAGE
PIN NAMES
RCLK
-BAUDOUT
CS0
CS1
IOR
IOW
-TXRDY
-RXRDY
-AS
-DDIS
-OP1
-OP2
48-TQFP PIN#
DESCRIPTION
5
The RCLK needs to be connected to the BAUDOUT external to the uart on the 16550.
12
This is done internally in the XR16L580.
9
These are redundant Chip Select signals on the 16550 and have been removed in the
10
XR16L580.
20
These are redundant control signals on the 16550 and have been removed in the
17
XR16L580.
23
These are status indicator outputs on the 16550 that are rarely used in most applica-
29
tions and have been removed in the XR16L580.
24
The Address Strobe signal is used to latch the address inside the uart on the 16550.
The XR16L580 automatically latches the address internally and hence this signal has
been removed.
22
Data Disable output. Rarely used in today’s applications.
34
General Purpose outputs. Rarely used in today’s applications.
31
2