A1363 Datasheet, PDF (22/30 Pages) Allegro MicroSystems – Low Noise, High Precision, Programmable Linear Hall Effect Sensor IC

A1363
Low Noise, High Precision, Programmable Linear Hall Effect Sensor IC
With Advanced Temperature Compensation
And High Bandwidth (120 kHz) Analog Output
Programming Serial Interface
The A1363 incorporates a serial interface that allows an external
controller to read and write registers in the EEPROM and volatile
memory. The A1363 uses a point-to-point communication pro-
tocol, based on Manchester encoding per G. E. Thomas (a rising
edge indicates 0 and a falling edge indicates 1), with address and
data transmitted MSB first.
WRITING THE ACCESS CODE
In order for the external controller to write or read from the
A1363 memory during the current session, it must establish serial
communication with the A1363 by sending a Write command
including the Access Code within Access Code Time Out, t_ACC ,
from power-up. If this deadline is missed, all write and read
access is disabled until the next power-up.
TRANSACTION TYPES
Each transaction is initiated by a command from the controller;
the A1363 does not initiate any transactions. Three commands
are recognized by the A1363: Write Access Code, Write, and
Read. One response frame type is generated by the A1363, Read
Acknowledge. If the command is Read, the A1363 responds by
transmitting the requested data in a Read Acknowledge frame. If
the command is any other type, the A1363 does not acknowledge.
As shown in Figure 16, the A1363 receives all commands via the
VCC pin. It responds to Read commands via the VOUT pin. This
implementation of Manchester encoding requires the communica-
tion pulses be within a high (V_MAN(H)) and low (V_MAN(L)) range
of voltages for the VCC line and the VOUT line. The Write com-
mand to EEPROM is supported by two high voltage pulses on the
VOUT line.
WRITING TO VOLATILE MEMORY
In order for the external controller to write to volatile memory,
a Write command must be transmitted on the VCC pin. Succes-
sive Write commands to volatile memory must be separated by
t_WRITE . The required sequence is shown in Figure 15.
VCC
Previous
Command
Write
to Register R#
Next
Command
t
t_WRITE
t_WRITE
Figure 15: Writing to Volatile Memory
Write/Read Command
– _{Manchester Code}
VCC
A1363
VOUT
GND
High Voltage pulses to
activate EEPROM cells
Read Acknowledge
– Manchester Code
Controller
Figure 16: Top-level Programming Interface
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