vsc055xkm-01 Maxim Integrated Products, Inc., vsc055xkm-01 Datasheet - Page 111

• Manufacturer Part Number: vsc055xkm-01
• Description: Enhanced I?c Backplane Controller
• Manufacturer: Maxim Integrated Products, Inc.

VSC055-01
Data Sheet
3.2.98 FCh: Backplane Controller Test (BCT)
3.2.99 FDh: Clock Select Control (CSC)
The following table shows the bit assignments for the Backplane Controller Test register.
The following table shows the bit assignments for the Clock Select Control register.
Register Name:
Address:
Reset Value:
Bit
7
6:3
2
1
0
Register Name:
Address:
Reset Value:
Bit
7
Bit Label
SRST
RES
FSB
FRB
SIFB
Bit Label
TFE
BCT
FCh
0XXX_X000b
CSC
FDh
0000_0000b
Access
R/W
R
R/W
Access
R/W
Description
Soft Reset
Setting this bit resets the device at the end of the current serial transfer. All
inputs and outputs, control registers, clock dividers, and the slave state
machine are reset by this bit.
This bit is self-clearing. Writing a 0 to this bit has no effect on the current state
of the device.
Reserved.
Fan Speed Bypass
Setting this bit causes the main clock divider for the fan speed monitors to be
bypassed. Bypassing the main clock divider causes the fan speed counters to
Flash Rate Bypass
Setting this bit causes the main clock divider for the flash rate generators to be
bypassed. Bypassing the main clock divider causes the expected flash rates to
be 125,000 times faster than normal.
When reset or after power on, the normal clock divider is activated.
This bit should not be set during normal operation.
Serial Interface Filter Bypass
Setting this bit causes the digital filters on the SCL and SDA pins to be
bypassed. Bypassing the filters allows the serial transfer speed to be increased
for test purposes.
When reset or after power on, normal filtering is activated.
Do not set this bit during normal operation.
operate 500 times faster than normal.
When reset or after power on, the normal clock divider is activated.
Do not set this bit during normal operation.
Description
Tach Filter Extend
Setting this bit causes the input filters on P2.0 through P2.7 to be extended
from a two-stage voting circuit to a five-stage voting circuit. Additional noise
immunity of approximately 300 ns is achieved.
This bit enables the filter extension logic on all tach inputs and is independent
of the tach control logic. The extended filters on P2.0 through P2.7 can be
used in other applications with noisy signaling that require an enhanced input
filter.
After a reset or power on, this register bit is cleared to a 0, enabling normal
input filter operation.
111 of 133
January 2008
Revision 4.1