Configuration Handbook - Kamami.pl

Configuring APEX 20KE & APEX 20KC DevicesTable 7–9. Dedicated Configuration Pins on the APEX 20KE & APEX 20KC Device (Part 3 of 5)Pin NameUserModeConfigurationSchemenCE N/A All Input Active-low chip enable. The nCE pin activates the devicewith a low signal to allow configuration. The nCE pin mustbe held low during configuration, initialization, and usermode. In single device configuration, it should be tiedlow. In multi-device configuration, nCE of the first deviceis tied low while its nCEO pin is connected to nCE of thenext device in the chain.The nCE pin must also be held low for successful JTAGprogramming of the FPGA.nCEO N/A All Output Output that drives low when device configuration iscomplete. In single device configuration, this pin is leftfloating. In multi-device configuration, this pin feeds thenext device's nCE pin. The nCEO of the last device in thechain is left floating.DCLK N/A Synchronousconfigurationschemes (PSand PPS)InputClock input used to clock data from an external sourceinto the target device. Data is latched into the FPGA onthe rising edge of DCLK.In PPA mode, DCLK should be tied high to V CC to preventthis pin from floating.After configuration, this pin is tri-stated. In schemes thatuse a configuration device, DCLK will be driven low afterconfiguration is done. In schemes that use a control host,DCLK should be driven either high or low, whichever ismore convenient. Toggling this pin after configurationdoes not affect the configured device.DATA0 N/A All Input Data input. In serial configuration modes, bit-wideconfiguration data is presented to the target device onthe DATA0 pin.After configuration, EPC1 and EPC1441 devices tri-statethis pin, while enhanced and EPC2 devices drive this pinhigh. In schemes that use a control host, DATA0 shouldbe driven either high or low, whichever is moreconvenient. Toggling this pin after configuration does notaffect the configured device.DATA[7..1] I/O Parallelconfigurationschemes(PPS andPPA)Pin TypeInputsDescriptionData inputs. Byte-wide configuration data is presented tothe target device on DATA[7..0].In serial configuration schemes, they function as user I/Opins during configuration, which means they are tristated.After PPA or PPS configuration, DATA[7..1] areavailable as a user I/O pins and the state of these pindepends on the Dual-Purpose Pin settings.Altera Corporation 7–61August 2005 Configuration Handbook, Volume 1