Libraries GuideChapter 7: Design Elements (LD to NOR16)
MD0
Mode 0, Input Pad Used for Readback Trigger Input
XC3000
| XC4000E
| XC4000X
| XC5200
| XC9000
| Spartan
| SpartanXL
| Spartan2
| Virtex
|
|---|
N/A
| Primitive
| Primitive
| Primitive
| N/A
| N/A
| N/A
| N/A
| N/A
|
The MD0 input pad is connected to the Mode 0 (M0) input pin, which is used to determine the configuration mode on XC4000 and XC5200 devices. Following configuration, MD0 can be used as an input pad, but it must be connected through an IBUF to the user circuit. However, the user input signal must not interfere with the device configuration. XC5200 devices allow an MD0 pad to be used as an output pad; XC4000 devices do not. The IOB associated with the MD0 pad has no flip-flop or latch. This pad is usually connected (automatically) to the RTRIG input of the READBACK function.
