Datasheet

ACLK

MULTIFUNCTION

I/O PORT BIT

ACLK

RD/WR

ANC/CTRL

AD[9:0]

READ

DATA DATA DATADATADATA DATA DATA

LMH0031

SNLS218A –JANUARY 2006–REVISED APRIL 2013

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Figure 5. Ancillary Data Read Timing

MULTI-FUNCTION I/O PORT

The multi-function I/O port can be configured to provide immediate access to many control and indicator

functions that are stored within the LMH0031’s configuration and control registers. The individual pins comprising

this port are assigned as input or output for selected functions stored in the control data registers.

The multi-function I/O port is configured by way of an 8x6-bit register bank consisting of registers I/O pin 0

CONFIG through I/O pin 7 CONFIG. The contents of these registers determine whether the port bits function as

inputs or outputs and to which control function or indicator each port bit is assigned. Port bits may be assigned to

access different functions and indicators or any or all port bits may be assigned to access the same function or

indicator (output mode only). The same indicator or function should not be assigned to more than one port bit as

an input. Controls and indicators that are accessible by the port and their corresponding selection addresses are

given in the I/O Pin Configuration Register Addresses, Table 6. Table 2 gives the control register bit

assignments.

Data resulting from device operation will be sent to the selected I/O port bit. This same data is also stored in the

configuration and control registers. Mapping the control and indicator functions in this manner means that device

operation will be immediately reflected at the I/O port pins thereby ensuring more reliable real-time operation of

the device within and by the host system.

When a multifunction I/O port bit is used as input to a control register bit, data must be presented to the I/O port

bit and clocked into the register bit using A

CLK

as shown in Figure 6. Port timing for bit write operations is the

same as for the ANC/CTRL port operation.

Figure 6. I/O Port Data Write Timing

Example: Program multi-function I/O port bit-0 as the CRC Luma Error bit output.