34.3.3.1 LDS
- Load Data from Data
Space Using Direct Addressing
The LDS
instruction is used to load data from the bus matrix and
into the serial shift register for serial readout. The LDS
instruction
is based on direct addressing, and the address must be given as an operand to the
instruction for the data transfer to start. Maximum supported size for address and data
is 16 bits. LDS
instruction supports repeated memory access when
combined with the REPEAT
instruction.
As shown in Figure 34-9, after issuing the SYNCH character followed by the
LDS
instruction, the number of desired address bytes, as indicated
by the SizeA field in the instruction, must be transmitted. The output data size is
selected by the SizeB field and is issued after the specified Guard Time. When combined
with the REPEAT
instruction, the address must be sent in for each
iteration of the repeat, meaning after each time the output data sampling is done. There
is no automatic address increment when using REPEAT
with
LDS
, as it uses a direct addressing protocol.