Datasheet

STPM10 Theory of operation
Doc ID 17728 Rev 4 35/53
7.20 Remote reset
The timing diagram of this operation is shown in Figure 22. The time step can be as short as
30 ns.
The internal reset signal is called RRR. Unlike the POR, the RRR signal does not cause the
30 ms delayed restart of the analog module, and the 120 ms delay in the restart of the digital
module. This signal does not clear the mode signals.
7.21 Reading data records
A microcontroller is able to read all measurement results and all system signals
(configuration, calibration, status, mode). Again, the time step can be as short as 30 ns.
There are two phases of reading, called latching and shifting.
Latching is used to sample results into transmission latches. The transmission latches are
the flip-flops that hold the data in the SPI interface. This is done with the active pulse on
SYN when SCS is idle. The length of the pulse on SYN must be longer than 2 periods of the
measurement clock, i.e. more than 500 ns at 4 MHz.
The shifting starts when SCS become active. In the beginning of this phase, another much
shorter pulse (30 ns) on SYN should be applied in order to ensure that an internal
transmission serial clock counter is reset to zero. An alternative way is to extend the pulse
on SYN into the second phase of reading. After this reset is done, a 32 serial clocks-per-
data record should be applied. Up to 8 data records can be read this way. This procedure
can be aborted at any time through deactivation of SCS (see Figure 24).
The first read-out byte of the data record is the least significant byte (LSB) of the data value
and, of course, the fourth byte is the most significant byte (MSB) of the data value. Each
byte can be further divided into a pair of 4-bit nibbles, referred to as the most and least
Figure 22. Timing for providing remote reset request
(1)
1. All time intervals must be longer than 30 ns. t
7
→ t
8
is the reset time; this interval must be longer than 30 ns also.
t
1
t
2
t
3
t
4
t
5
t
6
t
7
t
8
t
9
t
10
SCS
SYN
SCLNLC
SDATD
SCS
SYN
SCLNLC
SDATD