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MC68340FE16E Datasheet, PDF (334/441 Pages) Freescale Semiconductor, Inc – Integrated Processor with DMA User’s Manual | |||
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Freescale Semiconductor, Inc.
TxCTSâTransmitter Clear-to-Send
1 = Enables clear-to-send operation. The transmitter checks the state of the CTSâ
input each time it is ready to send a character. If CTSâ is asserted, the character
is transmitted. If CTSâ is negated, the channel TxDx remains in the high state,
and the transmission is delayed until CTSâ is asserted. Changes in CTSâ while
a character is being transmitted do not affect transmission of that character. If
both TxCTS and TxRTS are enabled, TxCTS controls the operation of the
transmitter.
0 = The CTSâ has no effect on the transmitter.
SB3âSB0âStop-Bit Length Control
These bits select the length of the stop bit appended to the transmitted character as
listed in Table 7-10. Stop-bit lengths of nine-sixteenth to two bits, in increments of one-
sixteenth bit, are programmable for character lengths of six, seven, and eight bits. For a
character length of five bits, one and one-sixteenth to two bits are programmable in
increments of one-sixteenth bit. In all cases, the receiver only checks for a high
condition at the center of the first stop-bit positionâi.e., one bit time after the last data
bit or after the parity bit, if parity is enabled.
If an external 1Ã clock is used for the transmitter, MR2 bit 3 = 0 selects one stop bit, and
MR2 bit 3 = 1 selects two stop bits for transmission.
Table 7-10. SBx Control Bits
SB3 SB2 SB1 SB0 Length 6-8 Bits
0
0
0
0
0.563
0
0
0
1
0.625
0
0
1
0
0.688
0
0
1
1
0.750
0
1
0
0
0.813
0
1
0
1
0.875
0
1
1
0
0.938
0
1
1
1
1.000
1
0
0
0
1.563
1
0
0
1
1.625
1
0
1
0
1.688
1
0
1
1
1.750
1
1
0
0
1.813
1
1
0
1
1.875
1
1
1
0
1.938
1
1
1
1
2.000
Length 5 Bits
1.063
1.125
1.188
1.250
1.313
1.375
1.438
1.500
1.563
1.625
1.688
1.750
1.813
1.875
1.938
2.000
MOTOROLA
MC68340 USERâS MANUAL
7-39
For More Information On This Product,
Go to: www.freescale.com
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