xr16m780 Exar Corporation, xr16m780 Datasheet - Page 37

• Manufacturer Part Number: xr16m780
• Description: 1.62v To 3.63v High Performance Uart With 64-byte Fifo
• Manufacturer: Exar Corporation

REV. 1.0.0
MSR[4]: CTS Input Status
CTS# pin may function as automatic hardware flow control signal input if it is enabled and selected by Auto
CTS (EFR bit-7). Auto CTS Flow Control allows starting and stopping of local data transmissions based on the
modem CTS# signal. A HIGH on the CTS# pin will stop UART transmitter as soon as the current character has
finished transmission, and a LOW will resume data transmission. Normally MSR bit-4 bit is the complement of
the CTS# input. However in the loopback mode, this bit is equivalent to the RTS# bit in the MCR register. The
CTS# input may be used as a general purpose input when the modem interface is not used.
MSR[5]: DSR Input Status
Normally this bit is the complement of the DSR# input. In the loopback mode, this bit is equivalent to the DTR#
bit in the MCR register. The DSR# input may be used as a general purpose input when the modem interface is
not used.
MSR[6]: RI Input Status
Normally this bit is the complement of the RI# input. In the loopback mode this bit is equivalent to bit-2 in the
MCR register. The RI# input may be used as a general purpose input when the modem interface is not used.
MSR[7]: CD Input Status
Normally this bit is the complement of the CD# input. In the loopback mode this bit is equivalent to bit-3 in the
MCR register. The CD# input may be used as a general purpose input when the modem interface is not used.
This register provides the advanced features of XR16M780. Lower four bits of this register are reserved.
Writing to the higher four bits enables additional functions.
MSR[3:0]: Reserved
MSR[4]: Enable/Disable Transmitter (Requires EFR[4] = 1)
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MSR[5]: Enable/Disable Receiver (Requires EFR[4] = 1)
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MSR[6]: Enable/Disable 9-bit mode (Requires EFR[4] = 1)
For the 9-bit mode information,
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MSR[7]: Enable/Disable fast IR mode (Requires EFR[4] = 1)
The M780 supports the new fast IR transmission with data rate up to 1.152 Mbps.
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This is a 8-bit general purpose register for the user to store temporary data. The content of this register is
preserved during sleep mode but becomes 0xFF (default) after a reset or a power off-on cycle.
4.10
4.11
Logic 0 = Enable Transmitter (default).
Logic 1 = Disable Transmitter.
Logic 0 = Enable Receiver (default).
Logic 1 = Disable Receiver.
Logic 0 = Normal 8-bit mode (default).
Logic 1 = Enable 9-bit or Multidrop mode.
Logic 0 = IrDA version 1.0, 3/16 pulse ratio, data rate up to 115.2 Kbps (default).
Logic 1 = IrDA version 1.1, 1/4 pulse ratio, data rate up to 1.152 Mbps. For more IR mode information, please
See ”Section 2.16, Infrared Mode” on page 21.
Modem Status Register (MSR) - Write Only
Scratch Pad Register (SPR) - Read/Write
See ”Section 2.15, Normal Multidrop Mode” on page 20.
1.62V TO 3.63V HIGH PERFORMANCE UART WITH 64-BYTE FIFO
37
XR16M780