15-15
LatticeECP2/M sysCONFIG Usage Guide
Figure 15-7. Serial Mode Daisy Chain
Slave Parallel Mode
In Slave Parallel mode a host system sends the configuration data in a byte-wide stream to the LatticeECP2/M.
The CCLK, CSN, CS1N, and WRITEN pins are driven by the host system. WRITEN, CSN, and CS1N must be held
low to write to the device; data is input from D[0:7]. D0 is the MSb and D7 is the LSb.
Slave Parallel mode can also be used for readback of the internal configuration. By driving the WRITEN pin low,
and CSN and CS1N low, the device will input the readback instructions on the D[0:7] pins; WRITEN is then driven
high and read data is output on D[0:7] (see Figure 15-8). In order to support readback, the PERSISTENT bit must
be set to ON in ispLEVER Design Planner or in the Diamond Spreadsheet View (Global Preferences tab).
Note:
SLAVE PARALLEL Mode is not available in the 100-pin TQFP and 208-pin PQFP package offerings since the
CSN, CS1N and WRITEN pins are not bonded out for these packages.
Figure 15-8. Parallel Port Read Timing Diagram
Lattice FPGA
Slave Serial
CCLK
DI/CSSPI0N
DONE
INITN
DOUT
CFG1
CFG0
CPU
DATA
CLK
CFG2
PROGRAMN
PROGRAM
STATUS
STATUS
Lattice FPGA
Slave Serial
DOUT
CFG1
CFG0
CFG2
CCLK
DI/CSSPI0N
DONE
INITN
PROGRAMN
N
ote: In the Sla
v
e Serial Mode, the Bypass option is not s
u
pported
w
hen
u
sing encrypted
b
itstream files
w
ith the
LatticeECP2/M S-Series de
v
ices. Please refer to the
LatticeECP2/M S-Series Config
u
ration Encryption Usage G
u
ide
,
T
N
1109, for more information a
b
o
u
t
u
sing encrypted
b
itstream files.
W
RITE
N
Read Data
CCLK
D[0:7]
BUSY
CS
N
CS1
N
Send Read
Command
CS
N
p
u
lse
w
idth is
dependent on the time
re
qu
ired to disa
b
le the
external D[0:7] dri
v
er.
