LFXP3E-3QN208I Lattice, LFXP3E-3QN208I Datasheet - Page 316

• Manufacturer Part Number: LFXP3E-3QN208I
• Description: IC FPGA 3.1KLUTS 136I/O 208-PQFP
• Manufacturer: Lattice

Specifications of LFXP3E-3QN208I

• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

Lattice Semiconductor
Table 13-9. Software Preference List for the LatticeXP
PERSISTENT Bit
In order to use the sysCONFIG port while in user mode to read SRAM or Flash memory, the PERSISTENT bit must
be set to ON. PERSISTENT = ON preserves all of the sysCONFIG pins so the FPGA can be accessed by an exter-
nal device at any time. PERSISTENT = ON lets the software know that all of the dual-purpose configuration pins
are reserved and NOT available for use by the fitter or the user. PERSISTENT = ON reserves all of the dual-pur-
pose sysCONFIG pins, without regard to CONFIG_MODE.
Configuration Mode
The device knows which physical sysCONFIG port will be used by reading the state of the CFG[1:0] pins, but the
fitter software also needs to know which port will be used. The fitter cannot sample the configuration pins so the
user must tell the fitter by selecting the proper CONFIG_MODE. CONFIG_MODE tells the fitter which sysCONFIG
pins are not available for use as user I/O.
There are several additional configuration options, such as overflow, that are set by software. These options are
selected by clicking Properties under Generate Bitstream Data in ispLEVER. If either overflow option is selected,
then the DONE_EX and WAKE_UP selections will be set to correspond (see Table 13-10). Refer to the Configura-
tion Modes and Options section of this document for more details.
Table 13-10. Overflow Option Defaults
DONE Open Drain
The “DONE_OD” preference allows the user to configure the DONE pin as an open drain pin. The “DONE_OD”
preference is only used for the DONE pin. When the DONE pin is driven low, internally or externally, this indicates
that configuration is not complete and the device is not ready for the wake up sequence. Once configuration is com-
plete, with no errors, and the device is ready for wake up, the DONE pin must be driven high. For other devices to
be able to control the wake up process an open drain configuration is needed to avoid contention on the DONE pin.
The “DONE_OD” preference for the DONE pin defaults to ON. The DONE_OD preference is automatically set to
ON if the DONE_EX preference is set to ON. See Table 13-11 for more information on the relationship between
DONE_OD and DONE_EX.
DONE External
The LatticeXP device can wake up on its own after the Done bit is set or wait for the DONE pin to be driven high
externally. Set DONE_EX = ON to delay wake up until the DONE pin is driven high by an external signal synchro-
Overflow Option
On (either)
PERSISTENT
CONFIG_MODE
DONE_OD
DONE_EX
MCCLK_FREQ
CONFIG_SECURE
WAKE_UP
PWRSAVE
Off
Off
Preference Name
Off (Default)
On
On (automatically set by software)
DONE_EX Preference
OFF [off, on]
NONE[SLAVE_PARALLEL, SLAVE_SERIAL, MASTER_SERIAL,
NONE]
ON [off, on]
Lowest Frequency (see Table 13-3)
OFF [off, on]
21 (DONE_EX = off)
4 (DONE_EX = on)
OFF [off, on]
OFF [off, on]
13-17
Default Setting [List of All Settings]
Default 21 (user selectable 1 through 25)
Default 21 (user selectable 1 through 25)
Default 4 (User selectable 1 through 7)
LatticeXP sysCONFIG Usage Guide
WAKE_UP Preference