XR20M1172G28-0B Datasheet, PDF (34/55 Pages) Exar Corporation – TWO CHANNEL I2C/SPI UART WITH 64-BYTE FIFO

XR20M1172
TWO CHANNEL I2C/SPI UART WITH 64-BYTE FIFO
REV. 1.2.0
MCR[2]: OP1# / TCR and TLR Enable
OP1# is not available as an output pin on the M1172. But it is available for use during Internal Loopback Mode
(MCR[4] = 1). In the Internal Loopback Mode, this bit is used to write the state of the modem RI# interface
signal.
This bit is also used to select between the MSR and TCR registers at address offset 0x6 and the SPR and TLR
registers at address offset 0x7. Table 12 and Table 13 below shows how these registers are accessed.
TABLE 12: REGISTER AT ADDRESS OFFSET 0X6
EFR[4] MCR[2] _{Register at Address Offset 0x6}
0
X Modem Status Register (MSR)
1
0 Modem Status Register (MSR)
1
1 Trigger Control Register (TCR)
TABLE 13: REGISTER AT ADDRESS OFFSET 0X7
EFR[4] MCR[2] _{Register at Address Offset 0x7}
0
X Scratchpad Register (SPR)
1
0 Scratchpad Register (SPR)
1
1 Trigger Level Register (TLR)
MCR[3]: OP2#
OP2# is not available as an output pin on the M1172 but can be controlled in Internal Loopback Mode (MCR[4]
= 1).
• Logic 0 = OP2# set HIGH(default).
• Logic 1 = OP2# set LOW.
MCR[4]: Internal Loopback Enable
• Logic 0 = Disable loopback mode (default).
• Logic 1 = Enable local loopback mode, see loopback section and Figure 19.
MCR[5]: Xon-Any Enable (requires EFR bit-4=1 to write to this bit)
• Logic 0 = Disable Xon-Any function (default).
• Logic 1 = Enable Xon-Any function. In this mode, any RX character received will resume transmit operation.
The RX character will be loaded into the RX FIFO, unless the RX character is an Xon or Xoff character and
the M1172 is programmed to use the Xon/Xoff flow control.
MCR[6]: IR Mode Enable (requires EFR bit-4=1 to write to this bit)
This bit enables the infrared mode and/or controls the infrared mode after power-up. See “Section 2.15,
Infrared Mode” on page 22 for complete details.
• Logic 0 = Reserved (default).
• Logic 1 = Enable IR Mode.
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