Configuration Handbook - Kamami.pl

Configuring Stratix II & Stratix II GX Devices1 If the optional CLKUSR pin is used and nCONFIG is pulled lowto restart configuration during device initialization, you need toensure CLKUSR continues toggling during the time nSTATUS islow (maximum of 100 µs).When the device is in user-mode, initiating a reconfiguration is done bytransitioning the nCONFIG pin low-to-high. The nCONFIG pin should below for at least 2 µs. When nCONFIG is pulled low, the device also pullsnSTATUS and CONF_DONE low and all I/O pins are tri-stated. OncenCONFIG returns to a logic high level and nSTATUS is released by thedevice, reconfiguration begins.Figure 7–4 shows how to configure multiple devices using a MAX IIdevice. This circuit is similar to the FPP configuration circuit for a singledevice, except the Stratix II or Stratix II GX devices are cascaded formulti-device configuration.Figure 7–4. Multi-Device FPP Configuration Using an External HostMemoryADDR DATA[7..0]V CC (1) V CC (1)10 kΩ 10 kΩStratix II orStratix II GX Device 1Stratix II orStratix II GX Device 2MSEL[3..0]GNDGNDExternal Host(MAX II Device orMicroprocessor)GNDDATA[7..0]nCONFIGCONF_DONEnSTATUSnCEnCEODATA[7..0]nCONFIGDCLKMSEL[3..0]CONF_DONEnSTATUSnCEnCEON.C.DCLKNote to Figure 7–4:(1) The pull-up resistor should be connected to a supply that provides an acceptable input signal for all devices in thechain. V CC should be high enough to meet the V IH specification of the I/O standard on the device and the externalhost.In multi-device FPP configuration, the first device’s nCE pin is connectedto GND while its nCEO pin is connected to nCE of the next device in thechain. The last device’s nCE input comes from the previous device, whileits nCEO pin is left floating. After the first device completes configurationin a multi-device configuration chain, its nCEO pin drives low to activatethe second device’s nCE pin, which prompts the second device to beginconfiguration. The second device in the chain begins configuration withinone clock cycle; therefore, the transfer of data destinations is transparentto the MAX II device. All other configuration pins (nCONFIG, nSTATUS,DCLK, DATA[7..0], and CONF_DONE) are connected to every device inAltera Corporation 7–19May 2007 Stratix II Device Handbook, Volume 2