OXCB950
OXFORD SEMICONDUCTOR LTD.
7.3 Reset Configuration
7.3.1 Hardware Reset
7.3.2 Software Reset
After a hardware reset, all writable registers are reset to
0x00, with the following exceptions:
An additional feature available in the OXCB950 UART is
software resetting of the serial channel. This command has
the same effect on a single channel as a hardware reset
except it does not reset the clock source selections (i.e.
CKS register and CKA register). To reset the UART write
0x00 to the Channel Software Reset register ‘CSR’.
DLL, which is reset to 0x01.
CPR, which is reset to 0x20.
The state of read-only registers following a hardware reset
is as follows:
RHR[7:0]: Indeterminate
RFL[6:0]: 00000002
TFL[6:0]: 00000002
LSR[7:0]: 0x60 signifying that both the transmitter and the
transmitter FIFO are empty
MSR[3:0]: 00002
MSR[7:4]: Dependent on modem input lines DCD, RI,
DSR and CTS respectively
ISR[7:0]: 0x01, i.e. no interrupts are pending
ASR[7:0]: 1xx000002
RFC[7:0]: 000000002
GDS[7:0]: 000000012
DMS[7:0]: 000000102
CKA[7:0]:000000002
The reset state of output signals are tabulated below:
Signal
SOUT
RTS#
DTR#
Reset state
Inactive High
Inactive High
Inactive High
Table 12: Output Signal Reset State
DS-0033 Sep 05
External-Free Release
Page 34
OXFORD [ OXFORD SEMICONDUCTOR ]
