Semiconductor Group
6-33
1999-04-01
On-Chip Peripheral Components
C541U
Special Function Register STB (Address 94H)
Reset Value : XXH
Special Function Register SRB (Address 95H)
Reset Value : XXH
After reset the contents of the shift register and the receive buffer register are undefined.
The register SSCMOD is used to enable test modes during factory test. It must not be written or
modified during normal operation of the C541U.
Special Function Register SSCMOD (Address 96H)
Reset Value : 00H
Bit
Function
LOOPB
SSC loopback enable
This bit should be used for test purposes only.
LOOPB = 0 : The SSC operates as specified.
LOOPB = 1 : The STO output is connected internally via an inverter to the
SRI input, allowing to check the transfer locally without a second
SSC device.
TRIO
SSC disable tristate mode of SSC inputs
This bit should be used for test purposes only.
TRIO = 0 :
The SSC operates as specified.
TRIO = 1 :
The SSC inputs will be connected to the output latch of the
corresponding port pin. This allows a test of the SSC in slave
mode by simulating a transfer via a program setting the port
latches accordingly.
5-1
All bits of this register are set to 0 after reset. When writing SSCMOD, these
bits must be written with 0.
LSBSM
SSC LSB shift mode
If LSBSM is cleared, the SSC will shift out the MSB of the data first LSB last. If
LSBSM is set, the SSC will shift out LSB first and MSB last.
.7
.6
.5
.4
94H
STB
Bit No.
7
6
5
4
3
2
1
0
MSB
LSB
.3
.2
.1
.0
.7
.6
.5
.4
95H
SRB
.3
.2
.1
.0
LOOPB TRIO
0
0
96H
SSCMOD
Bit No.
7
6
5
4
3
2
1
0
MSB
LSB
0
0
0
LSBSM
Summary of Contents for C541U
Page 1: ... 8 LW 026 0LFURFRQWUROOHU 8VHU V 0DQXDO http www siem ens d Sem iconductor ...
Page 7: ......
Page 21: ...Semiconductor Group 2 6 1997 10 01 Fundamental Structure C541U ...
Page 37: ...Semiconductor Group 4 6 1997 10 01 External Bus Interface C541U ...
Page 133: ...Semiconductor Group 6 88 1999 04 01 On Chip Peripheral Components C541U ...
Page 163: ...Semiconductor Group 8 8 1997 10 01 Fail Safe Mechanisms C541U ...
Page 185: ...Semiconductor Group 10 14 1997 10 01 OTP Memory Operation C541U ...