ST
- Store Data from Data Space Using Indirect
AddressingThe ST
instruction is used to store data that is shifted serially
into the PHY layer to the bus matrix address space. The ST
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 ST
instruction is used with
REPEAT
. ST
is also used to store the UPDI address
pointer into the pointer register. Maximum supported size for storing address and data
is 16 bit.
ST
Instruction
Operation
ST
to the UPDI pointer
register, and store of regular data. In both cases an Acknowledge (ACK) is sent back by
the UPDI if the store was successful, and a SYNCH character is sent before each
instruction. To write the UPDI pointer register, the following procedure should be
followed.When used with the REPEAT
, it is recommended to set up the address
register with the start address for the block to be written, and use pointer post
increment register to automatically increase the address for each repeat cycle. When
using repeat, the data frame of SizeD data bytes can be sent after each received
ACK.