RR0       SCC Buffer Status
----------------------------------------------------------------------
Bits  | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
------+---+---+---+---+---+---+---+---+
Flags | B |EOM|CTS| S |DCD| E | Z |RCA|

B    Break/Abort status
EOM  End Of Message / Transmit underrun status
CTS  Clear To Send
S    Sync pin / Hunt status
DCD  Data Carrier Detect
E    Transmit buffer empty
Z    Zero Count (Baud Rate Generator)
RCA  Receive Character Available

**********************************************************************

RR1       SCC Special Receive Condition
----------------------------------------------------------------------
Bits  | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
------+---+---+---+---+---+---+---+---+
Flags |EOF|CRC|OE |PE |    RC     | S |

EOF  End of Frame (SDLC mode).
CRC  CRC (Sync) or Framing (Async) error.
OE   Receiver Overrun Error (FIFO overflow).
PE   Parity Error
RC   Residue Codes (SDLC mode).
S    All Sent (Async)

**********************************************************************


RR10      SCC Misc. Status Bits
----------------------------------------------------------------------
Bits  | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
------+---+---+---+---+---+---+---+---+
Flags |CL1|CL2|   |LS |       | L |   |

CL1  One Clock Missing (DPLL)
CL2  Two Clocks Missing (DPLL)
LS   Loop Sending Status (1 = SCC actively sending)
L    On Loop Status (SDLC mode).