Rainbow Electronics ATR0625 - Manual (Page 16)

16
4925A–GPS–02/06
ATR0625 [Preliminary]
3.4.1 Connecting an Optional Serial EEPROM
The ATR0625 offers the possibility to connect an external serial EEPROM. The internal ROM
firmware supports to store the configuration of the ATR0625 in serial EEPROM. The pin
P16/NEEPROM signals the firmware that a serial EEPROM is connected with the ATR0625.
The 32-bit RISC processor of the ATR0625 accesses the external memory with SPI (Serial
Peripheral Interface). Atmel recommend to use 32 Kbit 1.8V serial EEPROM, e.g. the Atmel
AT25320AY1-1.8.
Figure 3-3 shows an example of the serial EEPROM connection.
Figure 3-3. Example of a Serial EEPROM Connection
Note: The GPSMODE pin configuration feature can be disabled, because the configuration can be
stored in the serial EEPROM. VDDIO is the supply voltage for the pins: P23, P24, P25 and P29.
AT25320AY1-1.8
ATR0625
SCK
SI
SO
CS_N
NC
GND
GND
HOLD_N
WP_N
P23/SCK
P25/MISO/NAADET0
P24/MOSI
P29/NPCS3
P16/NEEPROM
P1/GPSMODE0
(see Power Supply)
+3V
NC: Not connected
LDO_IN
LDOBAT_IN
VDDIO
VDD18
LDO_OUT
LDO_EN
NSHDN
GND