Maxim Integrated Secure Microcontroller - Manual (Page 158)

Secure Microcontroller User’s Guide
158 of 187
Figure 17-3. DS5000T/DS2250T RTC Register Entry Flowchart
*To guarantee that the pattern recognition circuit is
reset to the first bit of the sequence it is highly
recommended that 65 read operations be
performed. This is in case the DS5000T has been
interrupted or reset while the clock was open.
Set ECE2 bit in the MCON
register to a logic 1
Perform a dummy read
operation to reset clock pattern
recognition circuit*
To open clock, write the 64-bit
serial pattern by using A2 and
A0 embedded address lines
Clear ECE2 to a zero to
access normal embedded
data memory map
Write to time registers one bit
at a time using write MOVX
instructions that clear A2 to a
logic 0. A0 should be the bit to
be written. Read time registers one bit at
a time using read MOVX
instructions that set A2 to
logic 1. Bit to read will be
returned in bit 7 of data byte.
Are clock time
registers to be
read/written?
Written
Read