Powering USBS6
USBS6 may be used bus-powered (see SW2 below) without the need of any external power supply other than USB. In this mode VCCO_IO on J3,PIN A3, B3, C3 sourcing capability is limited due to the fact, that USB power supply current is limited depending on which system is used as host. Typically USB hosts allow up to 500mA. In bus-powered mode, at first only FX2 is enabled. After successful connection to the operating system the further power-on sequencing behavior depends on UDK configuration. Until the release of UDK2.0 only the API could enable further power-on sequencing, therefore after plugging an USB cable it also was necessary to start an application like cesys- Monitor before the FPGA and other devices turned on. With v2.0 and upcoming releases of UDK framework the user now can decide which power-on behavior fits best. Power-on sequencing through API or as soon as USB cable is plugged in. Default mode is API- controlled.
Modes of operation
Mode | SW2 | Comment * | VCCO_IO |
Bus- powered | | USB is used as power supply input. | 3.3V@ ??? mA |
| | | |
Connect 5V power supply to VG- 96pin external expansion connector J3 PINS A1, B1 and C1.
Minimum required supply current: ???A
*The actual required supply current strongly depends on FGPA design and may exceed the minimum required.
**In self-powered mode the actual VCCO_IO current limit depends on sourcing capability of external 5V power supply and may be less.
If the attached USB2.0 host interface should not be used as power supply, it is possible to use USBS6 self-powered (see SW2 above). In this mode an external 5V power supply must be connected to the external expansion connector J3, PINS A1, B1 and C1. All onboard voltages are enabled as soon as an external power supply is applied. VCCO on BANK0 and BANK3 is tied together to VCCO_IO but routed independent from other supply voltages. Therefore in self-powered mode maximum current available on J3,PIN
A3, B3, C3 (VCCO_IO) mainly depends on the external power supply to the limit of the onboard regulator, which is about 3A. As default VCCO_IO is regulated to 3.3V to enable 3.3V signaling levels on the external expansion connectors. Other signaling levels may be supported but require adjustment of the onboard synchronous buck regulator to the desired value.
USBS6 / C1030-5510 | | http://www.cesys.com/ |
User Doc V0.3 | -6- | preliminary |
