Specifications
ispLSI 1024/883
Functional Block Diagram
Figure 1.ispLSI 1024/883 Functional Block Diagram
RESET
Generic
Logic Blocks
(GLBs)
IN 5
IN 4
I/O 47
I/O 46
I/O 45
I/O 44
C7
I/O 0
I/O 1
I/O 2
I/O 3
I/O 4
I/O 5
I/O 6
I/O 7
I/O 8
I/O 9
I/O 10
I/O 11
I/O 12
I/O 13
I/O 14
I/O 15
SDI/IN 0
SDO/IN 1
A0
A1
Output Routing Pool (ORP)
C6
Output Routing Pool (ORP)
C5
C4
C3
C2
C1
C0
I/O 43
I/O 42
I/O 41
lnput Bus
A2
A3
A4
A5
A6
A7
Global
Routing
Pool
(GRP)
I/O 40
I/O 39
I/O 38
I/O 37
I/O 36
I/O 35
I/O 34
I/O 33
I/O 32
Input Bus
B0
Megablock
B1
B2
B3
B4
B5
B6
B7
Clock
Distribution
Network
Output Routing Pool (ORP)
Input Bus
CLK 0
CLK 1
CLK 2
IOCLK 0
IOCLK 1
ispEN
SCLK/IN 2
MODE/IN 3
I/O I/O I/O I/O
16 17 18 19
I/O I/O I/O I/O
20 21 22 23
I/O I/O I/O I/O
24 25 26 27
I/O I/O I/O I/O
28 29 30 31
Y Y Y Y
0 1 2 3
0139D_1024.eps
The device also has 48 I/O cells, each of which is directly
connected to an I/O pin. Each I/O cell can be individually
programmed to be a combinatorial input, registered in-
put, latched input, output or
bi-directional
I/O pin with 3-state control. Additionally, all outputs are
polarity selectable, active high or active low. The signal
levels are TTL compatible voltages and the output drivers
can source 4 mA or sink 8 mA.
Eight GLBs, 16 I/O cells, two dedicated inputs and one
ORP are connected together to make a Megablock (see
figure 1). The outputs of the eight GLBs are connected
to a set of 16 universal I/O cells by the ORP. The I/O cells
within the Megablock also share a common Output
Enable (OE) signal. The ispLSI 1024/883 device con-
tains three of these Megablocks.
The GRP has as its inputs the outputs from all of the GLBs
and all of the inputs from the bi-directional I/O cells. All of
these signals are made available to the inputs of the
GLBs. Delays through the GRP have been equalized to
minimize timing skew.
Clocks in the ispLSI 1024/883 device are selected using
the Clock Distribution Network. Four dedicated clock pins
(Y0, Y1, Y2 and Y3) are brought into the distribution
network, and five clock outputs (CLK 0, CLK 1, CLK 2,
IOCLK 0 and IOCLK 1) are provided to route clocks to the
GLBs and I/O cells. The Clock Distribution Network can
also be driven from a special clock GLB (B4 on the ispLSI
1024/883 device). The logic of this GLB allows the user
to create an internal clock from a combination of internal
signals within the device.
2
LATTICE [ LATTICE SEMICONDUCTOR ]
