DATA COMMUNICATIONS APPLICATION NOTE

DAN132

3

1.3.3

Firmware Differences Between the TL16C550C and ST16C580

The internal registers in the TL16C550C and ST16C580 are similar but with some exceptions:

R = Read-Only, W = Write-Only, R/W = Read/Write

A2:A0

R/W

ST16C580

TL16C550C

LCR Bit-7 = 0

001

R/W

Interrupt Enable Register (IER)

Interrupt Enable Register (IER)

010

W

FIFO Control Register (FCR)

FIFO Control Register (FCR)

010

R

Interrupt Status Register (ISR)

Interrupt Status Register (ISR)

100

R/W

Modem Control Register (MCR)

Modem Control Register (MCR)

LCR = 0xBF

010

R/W

Enhanced Feature Register (EFR)

Enable, Software Flow Control Select

N/A

100

R/W

XON1

N/A

101

R/W

XON2

N/A

110

R/W

XOFF1

N/A

111

R/W

XOFF2

N/A