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XP2 Datasheet, PDF (43/92 Pages) Lattice Semiconductor – LatticeXP2 Family Data Sheet | |||
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Lattice Semiconductor
Architecture
LatticeXP2 Family Data Sheet
original backup conï¬guration and try again. This all can be done without power cycling the system. For more
information please see TN1144, LatticeXP2 Dual Boot Usage Guide.
For more information on device conï¬guration, please see TN1141, LatticeXP2 sysCONFIG Usage Guide.
Soft Error Detect (SED) Support
LatticeXP2 devices have dedicated logic to perform Cyclic Redundancy Code (CRC) checks. During conï¬guration,
the conï¬guration data bitstream can be checked with the CRC logic block. In addition, LatticeXP2 devices can be
programmed for checking soft errors in SRAM. The SED operation can run in the background during user mode
(normal operation). In the event a soft error occurs, the device can be programmed to either reload from a known
good boot image (from internal Flash or external SPI memory) or generate an error signal.
For further information on SED support, please see TN1130, LatticeXP2 Soft Error Detection (SED) Usage Guide.
On-Chip Oscillator
Every LatticeXP2 device has an internal CMOS oscillator that is used to derive a Master Clock (CCLK) for conï¬gu-
ration. The oscillator and CCLK run continuously and are available to user logic after conï¬guration is complete. The
available CCLK frequencies are listed in Table 2-14. When a different CCLK frequency is selected during the
design process, the following sequence takes place:
1. Device powers up with the default CCLK frequency.
2. During conï¬guration, users select a different CCLK frequency.
3. CCLK frequency changes to the selected frequency after clock conï¬guration bits are received.
This internal CMOS oscillator is available to the user by routing it as an input clock to the clock tree. For further
information on the use of this oscillator for conï¬guration or user mode, please see TN1141, LatticeXP2 sysCONFIG
Usage Guide.
Table 2-14. Selectable CCLKs and Oscillator Frequencies During Conï¬guration and User Mode
CCLK/Oscillator (MHz)
2.51
3.12
4.3
5.4
6.9
8.1
9.2
10
13
15
20
26
32
40
54
803
1633
1. Software default oscillator frequency.
2. Software default CCLK frequency.
3. Frequency not valid for CCLK.
2-40
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