MAX1153/MAX1154
Stand-Alone, 10-Channel, 10-Bit System Monitors
with Internal Temperature Sensor and V
DD
Monitor
14 ______________________________________________________________________________________
Clock pulses on SCLK shift data into DIN on the rising
edge of the SCLK and out of DOUT on the falling edge
of SCLK.
Data transfers require a logic low on CS. A high-to-low
transition of CS marks the beginning of a data transfer. A
logic high on CS at any time resets the serial interface.
See Figure 6 and the
Timing Characteristics
table for
detailed serial-interface timing information.
Input Data Format
Serial communications always begin with an 8-bit com-
mand word, serially loaded from DIN. A high-to-low
transition on CS initiates the data input operation. The
command word and the subsequent data bytes (for
write operations) are clocked from DIN into the
MAX1153/MAX1154 on the rising edges of SCLK. The
first rising edge on SCLK, after CS goes low, clocks in
the MSB of the command word (see the
Command
Word
section). The next seven rising edges on SCLK
complete the loading of the command word into the
internal command register. After the 8-bit command
word is entered, transfer 0 to 20 bytes of data, depend-
ing on the command. Table 2 shows the number of
data bytes for each command.
Output Data Format
Output data from the MAX1153/MAX1154 is clocked
onto DOUT on the falling edge of SCLK. Single-ended
and unipolar differential measurements are output in
straight binary MSB first, with two 8-bytes-per-conver-
sion result, with 2 sub-bits and the last 4 bits padded
with zeros. For temperature and bipolar differential volt-
age measurements, the output is two’s complement
binary in the same 2-byte format. The MSB of the out-
put data from a read command transitions at DOUT
after the falling edge of the 8th SCLK clock pulse fol-
lowing the CS high-to-low transition. Table 2 shows the
number of bytes to be read from DOUT for a given read
command.
Command Word
The command word (Table 1) controls all serial com-
munications and configuration of the MAX1153/
MAX1154, providing access to the 44 on-chip registers.
The first 4 MSBs of the command word specify the
command (Table 2), while the last 4 bits provide
address information.
The first rising edge on SCLK, after CS goes low, trans-
fers the command word MSB into DIN. The next seven
rising edges on SCLK shift the remaining 7 bits into the
internal command register (see the
Serial Digital
Interface
section).
