78M6612-IMR/F Maxim Integrated Products, 78M6612-IMR/F Datasheet - Page 46

• Manufacturer Part Number: 78M6612-IMR/F
• Description: IC POWER MEASUREMENT AC 68-QFN
• Manufacturer: Maxim Integrated Products

Specifications of 78M6612-IMR/F

• Mounting Style: SMD/SMT
• Package / Case: QFN-68
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

78M6612 Data Sheet
1.5.10 EEPROM Interface
The 78M6612 provides hardware support for a two-pin or a three-pin EEPROM interface. The EEPROM
interface uses the EECTRL and EEDATA registers for communication.
1.5.10.1 Two-Pin EEPROM Interface
The dedicated 2-pin serial interface communicates with external EEPROM devices. The interface is
multiplexed onto pins DIO4 (SCK) and DIO5 (SDA) controlled by the I/O RAM bits DIO_EEX[1:0] (see
the I/O RAM Table). Set DIO_EEX[1:0] = 01 to select the two-wire EEPROM interface. The MPU
communicates with the interface through two SFR registers: EEDATA and EECTRL. If the MPU wishes to
write a byte of data to EEPROM, it places the data in EEDATA and then writes the ‘Transmit’ command
(CMD = 0011) to EECTRL. This initiates the transmit operation. The transmit operation is finished when
the BUSY bit falls. Interrupt INT5 is also asserted when BUSY falls. The MPU can then check the
RX_ACK bit to see if the EEPROM acknowledged the transmission.
46
A byte is read by writing the Receive command (CMD[3:0] = 0001) to EECTRL and waiting for the BUSY
bit to fall. Upon completion, the received data is in EEDATA. The serial transmit and receive clock is 78
kHz during each transmission, and the clock is held in a high state until the next transmission. The bits
in EECTRL are shown in
The EEPROM interface can also be operated by controlling the DIO4 and DIO5 pins directly
(“bit-banging”). However, controlling DIO4 and DIO5 directly is discouraged, because it may tie
up the MPU to the point where it may become too busy to process interrupts.
Status
3-0
Bit
7
6
5
4
CMD[3:0]
RX_ACK
TX_ACK
ERROR
Name
BUSY
Table
Write
Read
W
R
R
R
R
/
41.
Reset
State
0
0
1
1
0
Table 41: EECTRL Status Bits
Negative
Negative
Positive,
Polarity
Positive
Positive
Table
CMD
see
Description
1 when an illegal command is received.
1 when serial data bus is busy.
0 indicates that the EEPROM sent an ACK bit.
0 indicates when an ACK bit has been sent to
the EEPROM.
Others
CMD
0000
0001
0011
0101
0110
1001
Operation
No-op. Applying the no-op
command will stop the I
(SCK, DIO4). Failure to issue the
no-op command will keep the SCK
signal toggling.
Receive a byte from EEPROM and
send ACK.
Transmit a byte to EEPROM.
Issue a ‘STOP’ sequence.
Receive the last byte from
EEPROM, do not send ACK.
Issue a ‘START’ sequence.
No Operation, set the ERROR bit.
2
C clock
DS_6612_001
Rev. 1.2