XA3S500E-4PQG208I Datasheet, PDF (28/37 Pages) Xilinx, Inc – Proven advanced 90-nanometer process technology

R
Table 31: Switching Characteristics for the PS in Variable Phase Mode
Symbol
Description
Units
Phase Shifting Range
MAX_STEPS⁽²⁾
Maximum allowed number of DCM_DELAY_STEP
steps for a given CLKIN clock period, where T = CLKIN
clock period in ns. If using
CLKIN_DIVIDE_BY_2 = TRUE, double the clock
effective clock period.
CLKIN < 60 MHz
CLKIN > 60 MHz
±[INTEGER(10 •
(T_CLKIN – 3 ns))]
±[INTEGER(15 •
(T_CLKIN – 3 ns))]
steps
steps
FINE_SHIFT_RANGE_MIN Minimum guaranteed delay for variable phase shifting
±[MAX_STEPS •
ns
DCM_DELAY_STEP_MIN]
FINE_SHIFT_RANGE_MAX Maximum guaranteed delay for variable phase shifting
±[MAX_STEPS •
ns
DCM_DELAY_STEP_MAX]
Notes:
1. The numbers in this table are based on the operating conditions set forth in Table 6 and Table 30.
2. The maximum variable phase shift range, MAX_STEPS, is only valid when the DCM is has no initial fixed phase shifting, i.e., the PHASE_SHIFT
attribute is set to 0.
3. The DCM_DELAY_STEP values are provided at the bottom of Table 27.
Miscellaneous DCM Timing
Table 32: Miscellaneous DCM Timing
Symbol
Description
Min
DCM_RST_PW_MIN⁽¹⁾
Minimum duration of a RST pulse width
3
DCM_RST_PW_MAX⁽²⁾
Maximum duration of a RST pulse width
N/A
N/A
DCM_CONFIG_LAG_TIME⁽³⁾ Maximum duration from V_CCINT applied to FPGA
N/A
configuration successfully completed (DONE pin goes
High) and clocks applied to DCM DLL
N/A
Max
Units
-
CLKIN
cycles
N/A seconds
N/A seconds
N/A minutes
N/A minutes
Notes:
1. This limit only applies to applications that use the DCM DLL outputs (CLK0, CLK90, CLK180, CLK270, CLK2X, CLK2X180, and CLKDV).
The DCM DFS outputs (CLKFX, CLKFX180) are unaffected.
2. This specification is equivalent to the Virtex-4 DCM_RESET specification. This specification does not apply for Spartan-3E FPGAs.
3. This specification is equivalent to the Virtex-4 TCONFIG specification. This specification does not apply for Spartan-3E FPGAs.
DS635 (v2.0) September 9, 2009
www.xilinx.com
Product Specification
28