ADV7180
Data Sheet
Register Select (SR7 to SR0)
REGISTER ACCESS
These bits are set up to point to the required starting address.
I2C SEQUENCER
The MPU can write to or read from all of the ADV7180 registers
except the subaddress register, which is write only. The subaddress
register determines which register the next read or write operation
accesses. All communications with the part through the bus start
with an access to the subaddress register. A read/write operation is
then performed from or to the target address, which increments
to the next address until a stop command on the bus is performed.
An I2C sequencer is used when a parameter exceeds eight bits
and is therefore distributed over two or more I2C registers, for
example, HSB[10:0].
When such a parameter is changed using two or more I2C write
operations, the parameter may hold an invalid value for the
time between the first I2C being completed and the last I2C
being completed. In other words, the top bits of the parameter
may hold the new value while the remaining bits of the parameter
still hold the previous value.
To avoid this problem, the I2C sequencer holds the updated bits
of the parameter in local memory, and all bits of the parameter
are updated together once the last register write operation has
completed.
REGISTER PROGRAMMING
The following sections describe the configuration for each
register. The communication register is an 8-bit, write-only
register. After the part is accessed over the bus and a read/write
operation is selected, the subaddress is set up. The subaddress
register determines to or from which register the operation
takes place. Table 105 lists the various operations under the
control of the subaddress register for the control port.
SUB_USR_EN, Address 0x0E[5]
The correct operation of the I2C sequencer relies on the following:
This bit splits the register map at Register 0x40.
•
All I2C registers for the parameter in question must be
written to in order of ascending addresses. For example, for
HSB[10:0], write to Address 0x34 first, followed by 0x35,
and so on.
USER MAP
USER SUB MAP
2
COMMON I C SPACE
ADDRESS 0x00 ≥ 0x3F
•
No other I2C can take place between the two (or more) I2C
writes for the sequence. For example, for HSB[10:0], write to
Address 0x34 first, immediately followed by 0x35, and so on.
ADDRESS 0x0E BIT 5 = 0b
ADDRESS 0x0E BIT 5 = 1b
2
2
I C SPACE
I C SPACE
ADDRESS 0x40 ≥ 0xFF
ADDRESS 0x40 ≥ 0x9C
NORMAL REGISTER SPACE
INTERRUPT AND VDP REGISTER SPACE
Figure 53. Register Access—User Map and User Sub Map
Rev. E | Page 78 of 120
ADI [ ADI ]
