ADuCM320 Hardware Reference Manual
UG-498
Rev. C | Page 145 of 196
Bits
Bit Name
Description
Reset
Access
3
DDCD
Delta DCD. If set, this bit self clears after COMMSR is read.
0x0
R
0: DCD has not changed state since COMMSR was last read
1: DCD changed state since COMMSR last read
2
TERI
Trailing edge RI. If set, this bit self clears after COMMSR is read.
0x0
R
0: RI has not changed from 0 to 1 since COMMSR last read
1: RI changed from 0 to 1 since COMMSR last read
1
DDSR
Delta DSR. If set, this bit self clears after COMMSR is read.
0x0
R
0: DSR has not changed state since COMMSR was last read
1: DSR changed state since COMMSR last read
0
DCTS
Delta CTS. If set, this bit self clears after COMMSR is read.
0x0
R
0: CTS has not changed state since COMMSR was last read
1: CTS changed state since COMMSR last read
Scratch Buffer Register
Address: 0x4000501C, Reset: 0x0000, Name: COMSCR
Table 203. Bit Descriptions for COMSCR
Bits
Bit Name
Description
Reset
Access
[15:8]
RESERVED
Reserved.
0x0
R
[7:0]
SCR
Scratch. The scratch register is an 8-bit register used to store intermediate
results. The value contained in the scratch register does not affect UART
functionality or performance. Only 8 bits of this register are implemented.
Bit 15 to Bit 8 are read only and always return 0x00 when read. Writable
with any value from 0 to 255. A read returns the last value written.
0x0
RW
Fractional Baud Rate Register
Address: 0x40005024, Reset: 0x0000, Name: COMFBR
Table 204. Bit Descriptions for COMFBR
Bits
Bit Name
Description
Reset
Access
15
FBEN
Fractional baud rate generator enable. The generating of fractional baud
rate can be described by the following formula, and the final baud rate of
UART operation is calculated as Baud rate = ((UCLK/CDPCLK)/(2 × (M +
N/2048)) 16 × COMDIV.
0x0
RW
[14:13]
RESERVED
Reserved.
0x0
R
[12:11]
DIVM
Fractional baud rate M divide bits 1 to 3. This bit should not be 0.
0x0
RW
[10:0]
DIVN
Fractional baud rate N divide bits 0 to 2047.
0x0
RW
Baud Rate Divider Register
Address: 0x40005028, Reset: 0x0001, Name: COMDIV
Table 205. Bit Descriptions for COMDIV
Bits
Bit Name
Description
Reset
Access
[15:0]
DIV
Baud rate divider. The COMDIV register should not be 0, which is not
specified. The range of allowed DIV values is from 1 to 65535.
0x1
RW