15

ATSAM3303

6091A–DRMSD–07/04

IO Status Register

Status register is read when A0 = 1, RD = 0, CS = 0.

• TE: Transmit empty

If 0, data from ATSAM3303 to host is pending and IRQ is high. Reading the data at A0 = 0 will set TE to 1 and clear IRQ.

• RF: Receiver full

If 0, then ATSAM3303 is ready to accept DATA from host.

Note:

If status bit RF is not checked by host, write cycle time should not be lower than 3 µs.

SmartMedia and Other

Peripheral Interfaces

This is a master 8-bit parallel interface, allowing connection to SmartMedia or other

peripherals such as LCD screens.

Pins used: I/O7-I/O0 (I/O), SMPD (input), SMCE, SMALE, SMCLE, SMRE, SMWE

(outputs)

All these pins are fully under firmware control, therefore timing compatibility is ensured

by firmware only.

EEPROM/DataFlash

Interface

This is a master synchronous serial interface, operating in SPI mode 0.

Pins used: DFCS, DFSI, DFSCK (outputs), DFSO (input)

The DFSCK frequency is firmware programmable from fck to fck/64, where fck is the

crystal frequency. Thus a large variety of EEPROM/DataFlash devices can be

accomodated.

Please refer to Atmel DataFlash datasheets for accurate SPI mode 0 timing.

Figure 7. Typical DataFlash Interface Timing

76

543

21

0

TE

RF

XX

XX

XX

LSB

MSB

DFSCK

DFSI

DFSO