SC16IS762 Philips Semiconductors, SC16IS762 Datasheet - Page 10

• Manufacturer Part Number: SC16IS762
• Description: (SC16IS752 / SC16IS762) Dual UART
• Manufacturer: Philips Semiconductors

NXP Semiconductors
SC16IS752_SC16IS762_6
Product data sheet
Fig 6. 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 6
sending the next data character. When CTS is active, the transmitter sends the next
character. To stop the transmitter from sending the following character, 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 Features 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. 06 — 19 December 2006
Dual 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
SC16IS752/SC16IS762
C-bus/SPI interface, 64-byte FIFOs, IrDA SIR
shows software flow control options.
start
bit 0 to bit 7
002aab041
stop
© NXP B.V. 2006. All rights reserved.
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