User guide

Spartan-6 FPGA Configuration User Guide www.xilinx.com 125
UG380 (v2.7) October 29, 2014
Readback Command Sequences
7
Shift configuration packets into the CFG_IN data
register, MSB first.
a:
0xFFFF
b: 0xAA99
b: 0x5566
c: 0x30A1
c: 0x0008
d: 0x31A1
d: 0xXXXX
e: 0x3022
e: 0x0000
e: 0x0000
f: 0x30A1
f: 0x0004
g: 0x4880
g: 0x0000
g: 0x0000
h: 0x2000
h: 0x2000
0 271
Shift the LSB of the last configuration packet while
exiting SHIFT-DR.
011
Move into the SELECT-IR state. X 1 3
Move into the SHIFT-IR state. X 0 2
8
Shift the first five bits of the CFG_OUT instruction,
LSB first.
00100
(CFG_OUT)
05
Shift the MSB of the CFG_OUT instruction while
exiting Shift-IR.
011
Move into the SELECT-DR state. X 1 2
Move into the SHIFT-DR state. X 0 2
9
Shift the contents of the FDRO register out of the
CFG_OUT data register.
…0
number of
readback
bits – 1
Shift the last bit of the FDRO register out of the
CFG_OUT data register while exiting SHIFT-DR.
X11
Move into the Select-IR state. X 1 3
Move into the Shift-IR state. X 0 2
10 End by placing the TAP controller in the TLR state. X 1 3
Table 6-6: Shutdown Readback Command Sequence (JTAG) (Cont’d)
Step Description
Set and Hold
# of Clocks
(TCK)
TDI TMS