Microchip Technology megaAVR 0 Series Manual page 448

29.3.3.1 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
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.
Figure 29-8. LDS Instruction Operation
L DS
Synch
L D S
(0x55)
29.3.3.2 - Store Data to Data Space Using Direct Addressing
STS
The STS instruction is used to store data that is shifted serially into the PHY layer to the bus matrix
address space. The STS instruction is based on direct addressing, where the address is the first set of
operands, and data is the second set. The size of the address and data operands are given by the size
fields presented in the figure below. The maximum size for both address and data is 16 bits.
STS supports repeated memory access when combined with the REPEAT instruction.
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2018 Microchip Technology Inc.
29-8, after issuing the SYNCH character followed by the LDS instruction, the number
OPCODE Size A
0 0 0 0
ADR SIZE
A d r _ 0 A d r _ n
Unified Program and Debug Interface (UPDI)
Size B
S i z e A - A d d r e s s s i z e
0 0 B y t e
0 1 W o r d ( 2 B y t e s )
1 0 R e s e r v e d
1 1 R e s e r v e d
S i z e B - D a t a s i z e
0 0 B y t e
0 1 W o r d ( 2 B y t e s )
1 0 R e s e r v e d
1 1 R e s e r v e d
D a t a _ 0
ΔGT
Datasheet Preliminary
®
megaAVR 0-Series
D a t a _ n
DS40002015A-page 448
R x
T x