User guide

Spartan-6 FPGA Configuration User Guide www.xilinx.com 35
UG380 (v2.7) October 29, 2014
SelectMAP Configuration Interface
3. For more details on CCLK termination, see Board Layout for Configuration Clock
(CCLK), page 54.
4. This schematic is from XAPP502
, Using a Microprocessor to Configure Xilinx FPGAs via
Slave Serial or SelectMAP Mode. It is one of many possible implementations.
5. The DONE pin is by default an open-drain output with an internal pull-up. An
additional external pull-up is recommended. The DONE pin has a programmable
active driver that can be enabled via the BitGen option -g DriveDone.
6. The INIT_B pin is a bidirectional, open-drain pin. An external pull-up resistor is
recommended.
7. The BitGen startup clock setting must be set for CCLK for SelectMAP configuration.
8. The CSI_B and RDWR_B signals can be tied to ground if only one FPGA is going to be
configured and readback is not needed.
9. The D[0:n] bus can be x8 or x16 for Slave SelectMAP configuration.
10. V
FS
is present in 6SLX75/T, 6SLX100/T, and 6SLX150/T devices, and is used for
eFUSE programming. See eFUSE, page 91 for more details.
11. V
BATT
is present in 6SLX75/T, 6SLX100/T, and 6SLX150/T devices, and is the power
source for AES key storage. If AES encryption is unused, V
BATT
can be tied to either
V
CCAUX
or ground, or left unconnected.
12. If VCCO_2 is 1.8V, V
CCAUX
must be 2.5V. If VCCO_2 is 2.5V or 3.3V, V
CCAUX
can be
either 2.5V or 3.3V.
13. The SUSPEND pin should be Low during power up and configuration. If the Suspend
feature is not used, the SUSPEND pin must be connected to ground.
SelectMAP Data Loading
The SelectMAP interface allows for either continuous or non-continuous data loading.
Data loading is controlled by the CSI_B, RDWR_B, and CCLK signals.
CSI_B
The Chip Select input (CSI_B) enables the SelectMAP bus. CSI_B should not be deasserted
in the middle of a sync word. When CSI_B is High, the Spartan-6 device ignores the
SelectMAP interface, neither registering any inputs nor driving any outputs. D[0:n] is
placed in a High-Z state, and RDWR_B is ignored.
•If CSI_B = 0, the device's SelectMAP interface is enabled.
•If CSI_B = 1, the device's SelectMAP interface is disabled.
For a multiple device SelectMAP configuration, refer to Chapter 9, Advanced
Configuration Interfaces.
If only one device is being configured through the SelectMAP interface and readback is not
required, or if ganged SelectMAP configuration is used, the CSI_B signal can be tied to
ground, as illustrated in Chapter 9, Advanced Configuration Interfaces.