cp2120 Silicon Laboratories, cp2120 Datasheet - Page 17

• Manufacturer Part Number: cp2120
• Description: Single Chip Spi To I2c Transfer Integrated Clock; No External Clock Required On-chip Voltage Monitor
• Manufacturer: Silicon Laboratories

6.4. I
Bytes received from I
inside this buffer is saved in the RXBUFF Internal Register.
6.5. I
SPI commands initiate all I
command has been successfully received across the SPI bus. Once the CP2120 has completed the I
transaction prompted by the command, the INT pin will be pulled low to indicate that command execution has
completed. If an I
ignored.
6.5.1. Write Bytes to I
This command transmits data to an I
followed by the number of bytes to be transmitted across I
the I
was indicated by the second byte of the command will result in an error condition, and the I2C transaction will not
be initiated.
Once the I
the results of the transaction.
6.5.2. Read Bytes from I
This command attempts to retrieve bytes from an I
0x01, followed by the number of bytes to read (1 to 255) and the address of the I
Once the I
the transaction. The CP2120 saves the number of bytes stored in the buffer in the internal register named
RXBUFF. A Read Buffer command can be issued to retrieve the bytes from the buffer.
Note that if the SPI Master issues a second Read Bytes from I
command, the bytes stored in the CP2120's buffer will be overwritten.
Internal Register Address: 0x06
2
C Slave. The SPI master then sends the data to be transmitted across I
2
2
C Receive Buffer Size
C Commands
RXB7
2
2
Bit 7
C transaction completes, the CP2120 pulls the INT pin low and sets I2CSTAT according to the results of
C transaction completes, the CP2120 pulls the INT pin low and sets the internal register according to
SPI Master
R
Internal Register Definition 6. RXBUFF: Receive Buffer Size Register
Reset Value:
2
C command is issued while an I
Bit 7-0:
2
C transactions are stored in the 255-byte data buffer. The number of bytes currently stored
RXB6
2
C
Bit 6
R
2
COMMAND
C
SPI Master
2
C transactions. The CP2120 executes I
0x00
RXB7-0: Receive Buffer Size
Indicates the number of bytes received during the last I
0x00
RXB5
Bit 5
R
2
OF BYTES
NUMBER
C slave device. The command begins with the command byte (0x00),
COMMAND
0x01
RXB4
Bit 4
R
2
C Slave device. The command begins with the command byte,
2
C command is in progress, the second I
ADDRESS +W
Rev. 0.3
SLAVE
OF BYTES
NUMBER
2
C, which can range from 1 to 255, and the address of
RXB3
Bit3
R
2
C command before issuing a Read Buffer
2
SLAVE ADDRESS
C transactions only after every byte of the
BYTE1
DATA
RXB2
Bit 2
R
2
+R
C. Sending more or fewer bytes than
2
C slave device.
...
RXB1
2
Bit 1
C read transaction.
R
BYTE N
2
DATA
C command will be
CP2120
RXB0
Bit 0
R
2
17
C