SC16IS740IPW PHILIPS [NXP Semiconductors], SC16IS740IPW Datasheet - Page 11

• Manufacturer Part Number: SC16IS740IPW
• Description: Single UART with I2C-bus/SPI interface, 64 bytes of transmit and receive FIFOs, IrDA SIR built-in support
• Manufacturer: PHILIPS [NXP Semiconductors]

NXP Semiconductors
SC16IS740_750_760_5
Product data sheet
Fig 10. CTS functional timing
(1) When CTS is LOW, the transmitter keeps sending serial data out.
(2) When CTS goes HIGH before the middle of the last stop bit of the current character, the transmitter finishes sending the
(3) When CTS goes from HIGH to LOW, the transmitter begins sending data again.
current character, but it does not send the next character.
7.2.2 Auto CTS
CTS
TX
7.3 Software flow control
Figure 10
sending the next data byte. When CTS is active, the transmitter sends the next byte. To
stop the transmitter from sending the following byte, CTS must be deasserted before the
middle of the last stop bit that is currently being sent. The auto CTS function reduces
interrupts to the host system. When flow control is enabled, CTS level changes do not
trigger host interrupts because the device automatically controls its own transmitter.
Without auto CTS, the transmitter sends any data present in the transmit FIFO and a
receiver overrun error may result.
Software flow control is enabled through the enhanced feature register and the Modem
Control Register. Different combinations of software flow control can be enabled by setting
different combinations of EFR[3:0].
Table 3.
EFR[3]
0
1
0
1
X
X
X
1
0
1
0
shows CTS functional timing. The transmitter circuitry checks CTS before
start
EFR[2]
0
0
1
1
X
X
X
0
1
1
0
Software flow control options (EFR[3:0])
bit 0 to bit 7
EFR[1]
X
X
X
X
0
1
0
1
1
1
1
Rev. 05 — 16 November 2006
Single UART with I
stop
EFR[0]
X
X
X
X
0
0
1
1
1
1
1
Table 3
2
TX, RX software flow control
no transmit flow control
transmit Xon1, Xoff1
transmit Xon2, Xoff2
transmit Xon1 and Xon2, Xoff1 and Xoff2
no receive flow control
receiver compares Xon1, Xoff1
receiver compares Xon2, Xoff2
transmit Xon1, Xoff1
receiver compares Xon1 or Xon2, Xoff1 or Xoff2
transmit Xon2, Xoff2
receiver compares Xon1 or Xon2, Xoff1 or Xoff2
transmit Xon1 and Xon2, Xoff1 and Xoff2
receiver compares Xon1 and Xon2, Xoff1 and Xoff2
no transmit flow control
receiver compares Xon1 and Xon2, Xoff1 and Xoff2
C-bus/SPI interface, 64-byte FIFOs, IrDA SIR
shows software flow control options.
SC16IS740/750/760
start
bit 0 to bit 7
002aab041
stop
© NXP B.V. 2006. All rights reserved.
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