DAN-133 Datasheet, PDF (4/8 Pages) Exar Corporation – EXAR’S QUARTS COMPARED

DATA COMMUNICATIONS APPLICATION NOTE
DAN133
1.4.3 Firmware Differences Between the ST16C654 and TL16C554A
The internal registers in the ST16C654 and TL16C554A are similar but with some exceptions:
TABLE 3: ST16C654 AND TL16C554A REGISTER SET DIFFERENCES
A2:A0 R/W
LCR Bit-7 = 0
001 R/W
010
W
010
R
100 R/W
LCR = 0xBF
010 R/W
100 R/W
101 R/W
110 R/W
111 R/W
ST16C654
Interrupt Enable Register (IER)
• Bit-7 = Auto CTS# Interrupt Enable
• Bit-6 = Auto RTS# Interrupt Enable
• Bit-5 = Xoff Interrupt Enable
FIFO Control Register (FCR)
• Bit-5 = TX FIFO Trigger Level Select Bit-1
• Bit-4 = TX FIFO Trigger Level Select Bit-0
Interrupt Status Register (ISR)
• Bit-5 = Auto RTS/CTS Interrupt
• Bit-4 = Xoff or Special Character Interrupt
Modem Control Register (MCR)
• Bit-7 = BRG Prescaler
• Bit-6 = IR Mode Enable
• Bit-5 = XonAny
Enhanced Feature Register (EFR)
• Auto RTS/CTS Enable, Enhanced Functions
Enable, Software Flow Control Select
XON1
XON2
XOFF1
XOFF2
TL16C554A
Interrupt Enable Register (IER)
• Bit-7 = Not Used
• Bit-6 = Not Used
• Bit-5 = Not Used
FIFO Control Register (FCR)
• Bit-5 = Not Used
• Bit-4 = Not Used
Interrupt Status Register (ISR)
• Bit-5 = Not Used
• Bit-4 = Not Used
Modem Control Register (MCR)
• Bit-7 = Not Used
• Bit-6 = Not Used
• Bit-5 = Auto RTS/CTS Flow Control Enable
N/A
N/A
N/A
N/A
N/A
R = Read-Only, W = Write-Only, R/W = Read/Write
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