Datasheet

SPI/I

C UART with 128-Word FIFOs

MAX3107

38 Maxim Integrated

The XON1 and XON2 register contents define the XON characters used for auto XON/XOFF flow control and/or the

special characters used for special character detection. See details in the FlowCtrl register description.

Bits 7–0: Bit[7:0]

These bits define the XON1 character if single-character XON auto software flow control is enabled in FlowCntrl[7:4].

If double-character flow control is selected in FlowCntrl[7:4], these bits constitute the LSB of the XON character. If

special character detection is enabled in MODE2[4] and auto flow control is not enabled, these bits define a special

character. If special character detection and auto software flow control are enabled, XON1 defines the XON flow con-

trol character.

XON1 Register

Table 3. SwFlow[3:0] Truth Table

X = Don’t care

ADDRESS: 0x14

MODE: R/W

BIT 7 6 5 4 3 2 1 0

NAME

Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 Bit0

RESET

0 0 0 0 0 0 0 0

SwFlow3 SwFlow2 SwFlow1 SwFlow0

DESCRIPTION

RECEIVER FLOW

CONTROL

TRANSMITTER FLOW

CONTROL/SPECIAL

CHARACTER DETECTION

0 0 0 0 No flow control/no character detection.

0 0 X X No receiver flow control.

1 0 X X Transmitter generates XON1, XOFF1.

0 1 X X Transmitter generates XON2, XOFF2.

1 1 X X Transmitter generates XON1, XON2, XOFF1, and XOFF2.

X X 0 0 No transmitter flow control.

X X 1 0

Receiver compares XON1 and XOFF1 and controls the

transmitter accordingly. XON1 and XOFF1 special character

detection.

X X 0 1

Receiver compares XON2 and XOFF2 and controls the

transmitter accordingly. XON2 and XOFF2 special character

detection.

X X 1 1

Receiver compares XON1, XON2, XOFF1, and XOFF2 and

controls the transmitter accordingly. XON1, XON2, XOFF1,

and XOFF2 special character detection.