Configuration Handbook - Kamami.pl

Passive Serial Configurationpulled high by a pull-up resistor, the MAX II device can try to reconfigurethe target device without needing to pulse nCONFIG low. If this option isturned off, the MAX II device must generate a low-to-high transition(with a low pulse of at least 2 µs) on nCONFIG to restart the configurationprocess.The MAX II device can also monitor the CONF_DONE and INIT_DONEpins to ensure successful configuration. The CONF_DONE pin must bemonitored by the MAX II device to detect errors and determine whenprogramming completes. If all configuration data is sent, but CONF_DONEor INIT_DONE have not gone high, the MAX II device must reconfigurethe target device.1 If the optional CLKUSR pin is being used and nCONFIG is pulledlow to restart configuration during device initialization, youneed to ensure that CLKUSR continues toggling during the timenSTATUS is low (maximum of 100 µs).When the device is in user-mode, you can initiate a reconfiguration bytransitioning the nCONFIG pin low-to-high. The nCONFIG pin must 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 7–18 shows how to configure multiple devices using a MAX IIdevice. This circuit is similar to the PS configuration circuit for a singledevice, except Stratix II or Stratix II GX devices are cascaded formulti-device configuration.7–50 Altera CorporationStratix II Device Handbook, Volume 2 May 2007