EW31244SL7QV Datasheet, PDF (32/252 Pages) Intel Corporation – Intel® 31244 PCI-X to Serial ATA Controller

Intel^® 31244 PCI-X to Serial ATA Controller
Serial EEPROM
Serial EEPROM
3
Figure 4.
The GD31244 is software compatible with all existing operating systems which support parallel
ATA devices. However, the additional functions offered by the GD31244 require OS-specific code
to take advantage of these beneficial functions. The code for initializing the system and booting
drives will normally be located within the BIOS of the Host system or with an expansion ROM on
the Host Bus Adapter card. A Serial EEPROM may be optionally connected to the GD31244 to
store this code which will be downloaded and executed by the host system during initialization.
Applications not requiring a downloadable program do not require the Serial EEPROM. The
program should be downloaded into system RAM and executed there. Execution from the
EEPROM should not be attempted. Details on expansion ROM operation and initialization may be
found in the PCI 2.2 specification, Section 6.3.
The Intel GD31244 contains a four pin, Serial Peripheral Interface (SPI) to connect to an optional
Serial EEPROM to store a downloadable program. At power-up, the GD31244 hardware
automatically detects whether the EEPROM is present and indicates to this status to the Host
System during initialization.
This SPI interface was designed for compatibility with an ST Microelectronics* M25P10-A or
Atmel* AT25F1024 device with 131,072 Bytes of memory or an equivalent device. For the
purposes of understanding Serial EEPROM operation, refer to the Datasheet for the ST
Microelectronics documents, M25P10-A (dated February 2002) and Application Note (AN-1511
Ensuring Compatibility Between M25P10 to M25P10-A and M25P05 to M25P05-A in Your
Application, dated February 2002) and the datasheet for the Atmel AT25F1024 (revision 1440G,
dated February, 2002). The basic connection is shown in Figure 4.
Serial EEPROM Interface
GD31244
SDO
SDI
SCS#
SCLK
Serial EEPROM
SI
SO
CS#
SCK
User Selectable
WP#
High
HOLD#
B1396-001
32
April 2004
Developer’s Manual