AS3525 datasheet(39/194 Pages) AMSCO

39 / 194 page

AS3525-A/-B C22O22

Data Sheet, Confidential

www.austriamicrosystems.com

Revision 1.13

- 194

7.2.8.4 Functional description

Communication with the Memory Stick

The communication protocol with the Memory Stick is started by write from the CPU to the command register. When the protocol finishes, the CPU

is notified that the protocol has ended by an interrupt request.

Data transfer request

When the protocol is started and enters the data transfer state, data is requested by issuing a DMA transfer request or an interrupt request to the

CPU. Data can also be requested to an external memory.

Memory Stick communication time out

The RDY time out time when the handshake state (read protocol: BS2, write protocol: BS3) is established in communication with the Memory Stick

can be designated as the number of Memory Stick transfer clocks. When a time out occurs, the CPU is notified that the protocol has ended due to a

time out error by an interrupt request.

CRC off

CRC off can be set as a test mode.

When CRC off is set, CRC is not added to the data transmitted to the Memory Stick.

PAD cells

The connections to the MemoryStick Interface are shared with the General Purpose I/O port-D (GPIO xpd[0:7]).

Figure 15 external memory stick connection

AS3525 Datenblatt(PDF) 39 Page - ams AG