MIC3000 Datasheet, PDF (50/68 Pages) Micrel Semiconductor – SFP Management IC

MIC3000
Micrel
USER Password (USRPW)
D[7]
Read/write
D[6]
Read/write
D[5]
Read/write
D[4]
Read/write
D[3]
D[2]
Read/write Read/write
D[1]
D[0]
Read/write Read/write
Default Value
0000 0000_b = 00_h
Serial Address
A2_h = 1010001_b
Byte Address
251 = FB_h
USER passwords are entered in this field. This field is compared to the USRPWSET field at serial address A2_h, byte
250. If the two fields match, access is allowed to the USER areas of the MIC3000 non-volatile memory at serial
addresses A0_h and A2_h. If a valid USER password has not been entered, writes to the serial ID fields and user
scratchpad areas of A0_h and A2_h will not be allowed and USRPWSET will be unreadable (returns all zeroes).
Power-On Hours MSB (POHh)
D[7]
read-only
D[6]
read/write
D[5]
read/write
D[4]
read/write
D[3]
read/write
D[2]
read/write
D[1]
read/write
D[0]
read/write
POH Fault Flag (POHFLT)
Default Value
0000 0000_b = 00_h
Serial Address
A2_h = 1010001_b
Byte Address
252 = FC_h
The lower seven bits of this register contain the most-significant bits of the 15-bit power-on hours measurement.
POHFLT is an error flag. The value in this register should be combined with the Power-on Hours, Low Byte, POHl, to
yield the complete result. If POHFLT is set, the power-on hour meter data has been corrupted and should be ignored.
It is recommended that a two-byte (or more) sequential read operation be performed on POHh and POHl to insure
coherency between the two registers. This register is non-volatile and will be maintained through power and reset
cycle.
Bit(s)
D[7]
D[6:0]
Function
Power-on hours fault flag
Power-on hours, high byte
Operation
1 = fault; 0 = no fault.
Non-volatile.
Power-On Hours LSB (POHl)
D[7]
read/write
D[6]
read/write
D[5]
read/write
D[4]
read/write
D[3]
read/write
D[2]
read/write
D[1]
read/write
D[0]
read/write
POH Fault Flag (POHFLT)
Default Value
0000 0000_b = 00_h
Serial Address
A2_h = 1010001_b
Byte Address
253 = FD_h
This register contains the least-significant eight bits of the 15-bit power-on hours measurement. The value in this
register should be combined with the Power-on Hours, High Byte, POHh, to yield the complete result. If POHFLT is
set, the power-on hour meter data has been corrupted and should be ignored. It is recommended that a two-byte (or
more) sequential read operation be performed on POHh and POHl to insure coherency between the two registers. This
register is non-volatile and will be maintained through power and reset cycles.
M9999-101204
50
October 2004