Xilinx ML310 manual Push Buttons, Switches, Front Panel Interface and Jumpers, SPI Addressing

Board Hardware

R

SPI Addressing

The SPI does not use an addressed based system like the IIC Bus Interface uses. Instead, devices are selected by dedicated Slave Select signals, comparable to a Chip Select signal. Each SPI Slave device needs its own Slave Select signal driven from the SPI master. This increases the total pin count, but decreases overhead and complexity, which increases the available bandwidth and decreases bus contention.

The ML310 employs a single SPI device which is a 25LC640, 64k bits EEPROM. For more details on this device, please review the data sheet available on the ML310 CDROM.

Table 2-15shows the FPGA and the EEPROM connected by the SPI bus.

U37

Virtex-II Pro

FPGA

XC2VP30

SPI Bus U19

SPI

EEPROM

25LC640

Figure 2-15:SPI EEPROM Device Interface

Table 2-24shows the connections between the SMBus/IIC controller. and the XC2VP30.

Table 2-24:SMBus and IIC Controller Connections

UCF Signal Name	XC2VP30 Pin (U37)	Schem Signal Name
spi_miso	AJ10	SPI_DATA_OUT
spi_mosi	AK10	SPI_DATA_IN
spi_sck	AF12	SPI_CLK
spi_ss[0]	AF13	SPI_DATA_CS_N

*Note: This signal connects to U20 therm_l on the LM87. See data sheet for additional details.

Push Buttons, Switches, Front Panel Interface and Jumpers

Push Buttons

System ACE Reset, SW1

SW1 provides a way to manually reset the System ACE CF (U38) device. When SW1 is actuated it drives the signal PB_SYSTEM_ACE_RESET low which causes the LTC1326 (U31) to generate a 100us active low pulse. The active low output of the LTC1326 drives the reset input of the System ACE CF (U38) device via signal SYSTEMACE_RESET_N.

When the System ACE CF device is reset, it causes a re-configuration of the XC2VP30 FPGA. The ace file used to program the device is selected via dipswitch, SW3, settings. Please review the System ACE CF data sheet for more details, as it is located on the ML310 CDROM and also available on http://www.xilinx.com

The front panel interface header (J23) can also drive the PB_SYSTEM_ACE_RESET signal. For more details on J23, please review section “Front Panel Interface Connector, J23”.

ML310 User Guide	www.xilinx.com	53
UG068 (v1.01) August 25, 2004	1-800-255-7778