4 Configuration Process
4.1 Power-up Sequence
UG290-2.5.2E
10(98)
4.1
Power-up Sequence
During the power-on process, the power-on reset (POR) circuit inside
the FPGA becomes active. The actie POR circuit makes sure the external
I/O pins are in a high-impedance state and monitors the
VCC/VCCX/VCCOn input rails. When VCC/VCCX/VCCOn meets the
minimum reset voltage level (Voltage level may vary for different devices,
and different devices monitor different power rails.), POR circuit releases
an internal reset signal, allowing the FPGA to bigin its initialization process.
When READY and DONE are driven low, the FPGA moves to the
initialization state, as shown in Figure 5-2.
Figure 4-1 POR Power-up Timing
tINTL
VCC/VCCX/VCCOn
READY
DONE
Table 4-1 lists different power rails monitored by POR circuits of
different devices.
Table 4-1 Power Rails Monitored by POR Circuits of Different Devices
Series
Device
Power Rails
GW1N
GW1N-1
GW1N-4
GW1N-9
VCC/VCCX/VCCO1/VCCO3
GW1N-1P5
GW1N-2
VCC/VCCX/VCCO0
GW1N-1S
VCC/VCCX/VCCO0/VCCO2
GW1NZ
GW1NZ-1
VCC/VCCX/VCCO1/VCCO3
GW1NR
GW1NR-1
GW1NR-4
GW1NR-9
VCC/VCCX/VCCO1/VCCO3
GW1NS
GW1NS-4
GW1NS-4C
VCC/VCCX/VCCO0/VCCO1
GW1NSR
GW1NSR-4
GW1NSR-4C
VCC/VCCX/VCCO0/VCCO1
GW1NSE
GW1NSE-4C
VCC/VCCX/VCCO0/VCCO1
GW1NSER
GW1NSER-4C
VCC/VCCX/VCCO0/VCCO1
GW1NRF
GW1NRF-4B
VCC/VCCX/VCCO1/VCCO3
GW2A
GW2A-18
GW2A-55
VCC/VCCX/VCCO3
GW2AR
GW2AR-18
VCC/VCCX/VCCO3
GW2AN
GW2AN-9X
VCC/VCCX/VCCO1/VCCO5