Rainbow Electronics MAX5970 - Manual (Page 41)

0V to 16V, Dual Hot-Swap Controller with 10-Bit
Current and Voltage Monitor and 4 LED Drivers
MAX5970
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Table 55. Circular Buffer Readout Sequence
Address Pointers
Use the send byte protocol to set the register address
pointers before read and write operations. For the con-
figuration registers, valid address pointers range from
0x00 to 0x45, and the circular buffer addresses are 0x46
to 0x49. Register addresses outside of this range result
in a NACK being issued from the MAX5970.
Circular Buffer Read
The circular buffer read operation is similar to the receive
byte operation. The read operation is triggered after any
one of the circular buffer base addresses is loaded.
During a circular buffer read, although all is transparent
from the external world, internally the auto increment
function in the I
2 C controller is disabled. Thus, it is pos-
sible to read one of the circular buffer blocks with a burst
read without changing the virtual internal address corre-
sponding to the base address. Once the master issues
a NACK, the circular reading stops, and the default
functions of I
2 C slave bus controller are restored. In 8-bit
read mode, every I 2 C read operation shifts out a single
sample from the circular buffer. In 10-bit mode, two
subsequent I
2 C read operations shift out a single 10-bit
sample from the circular buffer, with the high-order byte
read first, followed by a byte containing the right-shifted
two least-significant bits. Once the master issues a
NACK, the read circular buffer operation terminates and
normal I
2 C operation returns.
The data in the circular buffers is read back with the
next-to-oldest sample first, followed by progressively
more recent samples until the most recent sample is
retrieved, followed finally by the oldest sample (see
Table 55).
Package Information
For the latest package outline information and land pat-
terns, go to
www.maxim-ic.com/packages . Note that
a “+”, “#”, or “-” in the package code indicates RoHS
status only. Package drawings may show a different suf-
fix character, but the drawing pertains to the package
regardless of RoHS status.
Chip Information
PROCESS: BiCMOS
READ-OUT ORDER 1 ST OUT 2 ND OUT … 48 TH OUT 49 TH OUT 50 TH OUT
Chronological Number 1 2 … 48 49 0
PACKAGE TYPE PACKAGE CODE DOCUMENT NO.
36 TQFN-EP T3666-3 21-0114