R
Platform Flash XL High-Density Configuration and Storage Device
as close as possible to the package). The PCB track widths should
be sufficient to carry the required VPP program and erase currents.
FPGA Configuration Overview
Platform Flash XL enables the rich set of FPGA
configuration features without additional glue logic. The
device delivers the FPGA bitstream at power-on through a
16-bit data bus at data rates up to 800 Mb/s. The FPGA can
also be configured from one of many design/revision
bitstreams stored in the device. These revision bitstreams
are accessed through the FPGA's MultiBoot addressing
and fallback features available in specific system
configurations with Platform Flash XL. For detailed
descriptions of the FPGA configuration features and
configuration procedure, refer to the respective FPGA
configuration user guide.
3. At the start of the configuration process, the FPGA
samples its mode pins to determine its configuration
mode. For Master BPI-Up mode, the FPGA outputs an
address to read from the flash. For Slave SelectMAP
mode, onboard resistors set the initial flash read
address.
4. The Platform Flash XL latches the initial address from
the FPGA or from onboard resistor settings into its
internal address counter and the Platform Flash XL
outputs the first 16-bit word.
5. The bitstream is synchronously transferred from the
Platform Flash XL to the FPGA. During each
successive FPGA CCLK period, the Platform Flash XL
increments its internal address counter and outputs the
next 16-bit word of the bitstream for the FPGA to
consume.
At a high level, the general procedure for FPGA
configuration from Platform Flash XL is as follows:
1. A system event, such as power-up, initiates the FPGA
configuration process. The FPGA drives its INIT_B pin
Low while it clears its configuration memory. The
Platform Flash XL drives its READY_WAIT pin Low
during its reset period.
6. At the end of the configuration process, the FPGA starts
operation of the loaded bitstream and either drives
DONE High or releases DONE to High, indicating the
completion of the configuration procedure.
2. When ready, the FPGA and Platform Flash XL release
their respective INIT_B and READY_WAIT pins. An
external resistor pulls the connected
Platform Flash XL can configure the FPGA in Slave
SelectMAP (x16) (recommended for maximum
INIT_B-READY_WAIT signal from Low to High,
synchronizing the start of the FPGA configuration
process.
performance), Master SelectMAP (x16), or Master BPI-Up
(x16) configuration mode. See Table 4 for a summary of
attributes for different configuration modes and memories.
Table 4: Overview of FPGA Configuration from Platform Flash XL and Standard BPI Flash
Platform Flash XL
Third-Party Standard BPI
Flash
High-Performance
Configuration Mode
Standard BPI Flash
Compatibility Mode
(110-ns Access Time)
Slave SelectMAP mode
(x16 data bus width)
Master BPI-Up mode
(x16 data bus width)
Master BPI-Up mode
(x16 data bus width)
FPGA Configuration Mode
Guaranteed Bitstream
Transfer Bandwidth at Best
Clock Setting
800 Mb/s(1)
248 Mb/s(2)
78 Mb/s(3)
Virtex-5 FPGA Support
Virtex-6 FPGA Support
9
9
9
9
9
9
ISE Software Programming
Support
9
9
9
9
For limited setups(4)
MultiBoot Capable
9
Notes:
1. The 800 Mb/s rate is achieved using a Virtex-5 FPGA with an external 50 MHz configuration clock source. Specific speed grades of the
Virtex-6 FPGA or system-level considerations can limit the configuration performance to less than 800 Mb/s.
2. Bandwidth is based on an example Virtex-5 FPGA considering F
3. Bandwidth is based on an example Virtex-5 FPGA considering F
and BitGen ConfigRate = 31 MHz (nominal frequency).
and BitGen ConfigRate = 17 MHz (nominal frequency),
MCCKTOL
MCCKTOL
bpi_page_size = 4, and bpi_1st_read_cycle = 4. First word access time = 110 ns; Page word access time = 25 ns.
4. See XAPP973, Indirect Programming of BPI PROMs with Virtex-5 FPGAs.
DS617 (v3.0.1) January 07, 2010
www.xilinx.com
Product Specification
8
XILINX [ XILINX, INC ]
