Fast AMBA Peripherals
12-22
GMS30C7201 Data Sheet
12.3.5 Ir Address Match Value Register
The Ir Address Match Value Register (IrAmv) contains the 8-bit address match value
field which is used by the MIr and FIr to selectively filter out unwanted received frames.
Address Match Value (AMV)
The 8-bit address match value (AMV) field is programmed with an address value which
is used to selectively store only the data within receive frames which have the same
address value. The address match enable (AME) bit in IrCon must be set to enable this
function. For incoming frames which have the same address value as the AMV field,
the frame
’
s address, control and data is stored in the receive buffer. For those that do
not, the remainder of the frame is ignored, and the receive logic searches for the
beginning of the next frame in the received data stream.
A broadcast address exists which is always matched by the address match logic
regardless of the value programmed in AMV. When address matching is enabled, any
time a frame is received with an address containing all ones (FFh), the value
programmed in AMV is ignored and the frame data is automatically stored in the receive
buffer.
The address value is contained within the first byte of data in a frame following the flag.
AMV can be written at any time, and is used for comparison for the next frame which
occurs following its update.
Figure 12-4: Address match value field in the IrAmv Register
shows the address
match value field within Ir Address Match Value Register. The reset state of AMV is
unknown and must be initialized before enabling the Ir interface. Note that IrAmv may
be written while an Ir interface is enabled to allow the address match value to be
changed during active receive operation.
Figure 12-4: Address match value field in the IrAmv Register
6
TIM
Transmit buffer Interrupt Mask
0 - Transmit buffer half-full or less condition does not generate an interrupt (TFS bit
ignored)
1 - Transmit buffer half-full or less condition generates an interrupt (state of TFS sent
to interrupt controller)
7
AME
Address Match Enable
0 - Disable receiver address match function, store data from all incoming frames in
receive buffer
1 - Enable receiver address match function, do not buffer data unless address
recognized or incoming address contains all ones (0hFF)
Bit
Name
Description
Table 12-25: Ir Control Register (Continued)
Address: 0h80011008
IrAmv
Read/Write
Bit
7
6
5
4
3
2
1
0
AMV
Reset