Rainbow Electronics MAX3107 - Manual (Page 38)

38 _____________________________________________________________________________________
MAX3107
SPI/I
2
C UART with 128-Word FIFOs
and Internal Oscillator
The XON1 and XON2 register contents define the XON characters used for automatic 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 automatic 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 automatic flow control is not enabled, these
bits define a special character. If special character detection and automatic software flow control are enabled, XON1
defines the XON flow control 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.