HDM8515 Datasheet, PDF (46/75 Pages) Hynix Semiconductor – DVB/DSS Compliant Receiver

5.4 I2C Mode
The HDM8515 utilizes the subaddress technique when the I2C mode is employed. In all cases,
the HDM8515 behaves as the slave device (transmitter or receiver), whilst the host behaves as the
master device. The seven bit slave address of the HDM8515 is user selectable, being defined by
the inputs to HI_DATA[6:0] when the HDM8515 is in I2C mode.
Further information on the I2C bus formats and protocols is contained in the Philips
Semiconductors I2C specification.
In a 100pin configuration, SDA_I2CO and SCL_I2CO are added to provide a by-passing function.
When I2C bypass bit is set to zero, SDA_I2CO and SCL_I2CO are disabled.
5.4.1 I2C Write to HDM8515
The master initiates communication with the HDM8515 by generating a start condition and then
sending the HDM8515 the slave address defined by the seven bit hardwired address on HI_DATA
[6:0]. Per I2C convention, the eighth bit in the address byte is a read/not write bit, and should be
set to zero. The HDM8515 will acknowledge the correctly sent slave address, following which the
master sends an eight bit word address; this is the address of the first HDM8515 register to be
written to. Once the word address has been acknowledged by the HDM8515, the master can then
transmit the byte to be written to the word address. Once this byte is acknowledged by the
HDM8515, the word address is automatically incremented and further data bytes may be
transmitted by the master as necessary; one transmission may therefore contain a number of
bytes of data to be written to a sequential set of addresses (dummy bytes should be written to
addresses not defined in the HDM8515 register set to continue this process). The process is
terminated by the master generating a stop condition. Figure 24 depicts this protocol.
acknowledgement
from slave
acknowledgement
from slave
acknowledgement
from slave
7 Bits
S SLAVE ADDRESS 0 A
R/W
S - Start Condition
A - Acknowledge
P - Stop Condition
8 Bits
WORD ADDRESS A
DATA BYTE
repeat if
necessary
AP
auto increment
memory word address
FIGURE 24: I2C WRITE TO THE HDM8515
5.4.2 I2C Read from the HDM8515
To read information from the HDM8515, the master must first write the desired word address.
Hence the master must first generate a start condition and transmit the seven bit HDM8515 slave
address defined on HI_DATA[6:0], with the eighth bit (read/not write) set to zero. Once this has
been acknowledged by the HDM8515, the master transmits the first word address from which it
wishes to read information. The master must then generate a second start condition and
46