CS5463
8. AUTO-BOOT MODE USING E2PROM
When the CS5463 MODE pin is asserted (logic 1), the
CS5463 auto-boot mode is enabled. In auto-boot mode,
the CS5463 downloads the required commands and
register data from an external serial E2PROM, allowing
the CS5463 to begin performing energy measurements.
8.1 Auto-boot Configuration
A typical auto-boot serial connection between the
CS5463 and a E2PROM is illustrated in Figure 17. In au-
to-boot mode, the CS5463’s CS and SCLK are config-
ured as outputs. The CS5463 asserts CS (logic 0),
provides a clock on SCLK, and sends a read command
to the E2PROM on SDO. The CS5463 reads the us-
er-specified commands and register data presented on
the SDI pin. The E2PROM’s programmed data is utilized
by the CS5463 to change the designated registers’ de-
fault values and begin registering energy.
VD+
5K
EOUT1
EOUT2
CS5463
SCLK
SDI
SDO
MODE
CS
Mech. Counter
or
Stepper Motor
5K
EEPROM
SCK
SO
SI
CS
Connector to Calibrator
Figure 17. Typical Interface of E2PROM to CS5463
Figure 17 also shows the external connections that
would be made to a calibrator device, such as a PC or
custom calibration board. When the metering system is
installed, the calibrator would be used to control calibra-
tion and/or to program user-specified commands and
calibration values into the E2PROM. The user-specified
commands/data will determine the CS5463’s exact op-
eration, when the auto-boot initialization sequence is
running. Any of the valid commands can be used.
8.2 Auto-boot Data for E2PROM
Below is an example code set for an auto-boot se-
quence. This code is written into the E2PROM by the us-
er. The serial data for such a sequence is shown below
in single-byte hexidecimal notation:
-64 00 00 60
Write Operation Mode Register, turn high-pass
filters on.
-44 7F C4 A9
Write value of 0x7FC4A9 to Current Gain
Register.
-48 FF B2 53
Write value of 0xFFB253 to Voltage Gain
Register.
-74 00 00 04
Unmask bit #2 (LSD) in the Mask Register.
-E8
Start continuous conversions
-78 00 01 00
Write STOP bit to Control Register, to terminate
auto-boot initialization sequence.
8.3 Which E2PROMs Can Be Used?
Several industry-standard serial E2PROMs that will suc-
cessfully run auto-boot with the CS5461A are listed be-
low:
• Atmel AT25010, AT25020 or AT25040
• National Semiconductor NM25C040M8 or NM25020M8
• Xicor X25040SI
These types of serial E2PROMs expect a specific 8-bit
command (00000011) in order to perform a memory
read. The CS5461A has been hardware programmed to
transmit this 8-bit command to the E2PROM at the be-
ginning of the auto-boot sequence.
40
DS678F2