Visible to Intel only — GUID: iga1432671711787
Ixiasoft
Visible to Intel only — GUID: iga1432671711787
Ixiasoft
10.4.6. mcr
Identifier | Title | Offset | Access | Reset Value | Description |
---|---|---|---|---|---|
mcr | Modem Control Register | 0x10 | RW | 0x00000000 | Reports various operations of the modem signals. |
Bit Fields | |||||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
31 | 30 | 29 | 28 | 27 | 26 | 25 | 24 | 23 | 22 | 21 | 20 | 19 | 18 | 17 | 16 |
— | |||||||||||||||
15 | 14 | 13 | 12 | 11 | 10 | 9 | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
— | afce | loopback | out2 | out1 | rts | dtr |
Bit | Name/Identifier | Description | Access | Reset |
---|---|---|---|---|
[31:6] | — | Reserved | R | 0x0 |
[5] | Hardware Auto Flow Control Enable ( afce) | When FIFOs are enabled (FCR[0]), the Auto Flow Control enable bits are active. This enabled UART to dynamically assert and deassert rts_n based on Receive FIFO trigger level |
RW | 0x0 |
[4] | LoopBack Bit (loopback) | This is used to put the UART into a diagnostic mode for test purposes. If UART mode is NOT active, bit [6] of the modem control register MCR is set to zero, data on the sout line is held high, while serial data output is looped back to the sin line, internally. In this mode all the interrupts are fully functional. Also, in loopback mode, the modem control inputs (dsr_n, cts_n, ri_n, dcd_n) are disconnected and the modem control outputs (dtr_n, rts_n, out1_n, out2_n) are looped-back to the inputs, internally. |
RW | 0x0 |
[3] | Out2 (out2) | This is used to directly control the user-designated out2_n output. The value written to this location is inverted and driven out on out2_n |
RW | 0x0 |
[2] | Out1 (out1) | This is used to directly control the user-designated out1_n output. The value written to this location is inverted and driven out on out1_n pin. |
RW | 0x0 |
[1] | Request to Send (rts) | This is used to directly control the Request to Send (rts_n) output. The Request to Send (rts_n) output is used to inform the modem or data set that the UART is ready to exchange data. When Auto RTS Flow Control is not enabled (MCR[5] set to zero), the rts_n signal is set low by programming this register to a high. If Auto Flow Control is active (MCR[5] set to 1) and FIFO's enable (FCR[0] set to 1), the rts_n output is controlled in the same way, but is also gated with the receiver FIFO threshold trigger (rts_n is inactive high when above the threshold). The rts_n signal will be de-asserted when this register is set low. |
RW | 0x0 |
[0] | Data Terminal Ready (dtr) | This is used to directly control the Data Terminal Ready output. The value written to this location is inverted and driven out on uart_dtr_n. The Data Terminal Ready output is used to inform the modem or data set that the UART is ready to establish communications. |
RW | 0x0 |