Microchip Technology megaAVR 0 Series Manual page 449

Figure 29-9. STS Instruction Operation
STS
Synch
S T S
(0x55)
The transfer protocol for an STS instruction is depicted in the figure as well, following this sequence:
1. The address is sent.
2. An Acknowledge (ACK) is sent back from the UPDI if the transfer was successful.
3. The number of bytes as specified in the STS instruction is sent.
4. A new ACK is received after the data has been successfully transferred.
29.3.3.3 LD - Load Data from Data Space Using Indirect Addressing
The LD instruction is used to load data from the bus matrix and into the serial shift register for serial
readout. The LD instruction is based on indirect addressing, which means that the Address Pointer in the
UPDI needs to be written prior to bus matrix access. Automatic pointer post-increment operation is
supported and is useful when the LD instruction is used with REPEAT. It is also possible to do an LD of the
UPDI Pointer register. The maximum supported size for address and data load is 16 bits.
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2018 Microchip Technology Inc.
OPCODE Size A
0 1 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
A C K
ΔGT
Datasheet Preliminary
®
megaAVR 0-Series
DATA SIZE
D a t a _ n
ΔGT
DS40002015A-page 449
R x
T x
A C K