Specifications ispLSI 1048EA
2
USE
ispMA
CH
4A5
FOR
NEW
5V
DESIGNS
Functional Block Diagram
Figure 1. ispLSI 1048EA Functional Block Diagram
The device also has 96 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
input, latched input, output or bi-directional
I/O pin with 3-state control. The signal levels are TTL
compatible voltages and the output drivers can source
2mA or sink 8mA. Each output can be programmed
independently for fast or slow output slew rate to
minimize overall output switching noise. By connecting
the VCCIO pin to a common 5V or 3.3V power supply,
I/O output levels can be matched to 5V or 3.3V compat-
ible voltages.
Eight GLBs, 16 I/O cells, dedicated inputs (if available)
and one ORP are connected together to make a
Megablock (Figure 1). The outputs of the eight GLBs are
connected to a set of 16 universal I/O cells by the ORP.
Each ispLSI 1048EA device contains six 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 1048EA 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 (D0). The logic
of this GLB allows the user to create an internal clock
from a combination of internal signals within the device.
Programmable Open-Drain Outputs
In addition to the standard output configuration, the
outputs of the ispLSI 1048EA are individually program-
mable, either as a standard totem-pole output or an
open-drain output. The totem-pole output drives the
specified Voh and Vol levels, whereas the open-drain
output drives only the specified Vol. The Voh level on the
open-drain output depends on the external loading and
pull-up. This output configuration is controlled by a pro-
grammable fuse. The default configuration when the
device is in bulk erased state is totem-pole configuration.
The open-drain/totem-pole option is selectable through
the Lattice software tools.
Output Routing Pool (ORP)
B0
B1
B2
B3
B4
B5
B6
B7
Output Routing Pool (ORP)
C0
C1
C2
C3
C4
C5
C6
C7
Output Routing Pool (ORP)
F7
F6
F5
F4
F3
F2
F1
F0
Input Bus
Output Routing Pool (ORP)
E7
E6
E5
E4
E3
E2
E1
E0
Input Bus
A0
A1
A2
A3
A4
A5
A6
A7
Output
Routing
Pool
(ORP)
Generic
Logic Blocks
(GLBs)
Megablock
Input
Bus
Global
Routing
Pool
(GRP)
CLK 0
CLK 1
CLK 2
IOCLK 0
IOCLK 1
Clock
Distribution
Network
D7
D6
D5
D4
D3
D2
D1
D0
Output
Routing
Pool
(ORP)
I/O
94
I/O
95
I/O
93
I/O
92
I/O
91
I/O
90
I/O
89
I/O
88
I/O
87
I/O
86
I/O
85
I/O
84
I/O
83
I/O
82
I/O
81
I/O
80
IN
11
I/O
78
I/O
79
I/O
77
I/O
76
I/O
75
I/O
74
I/O
73
I/O
72
I/O
71
I/O
70
I/O
69
I/O
68
I/O
67
I/O
66
I/O
65
I/O
64
IN
9
IN
10
I/O
17
I/O
16
I/O
18
I/O
19
I/O
20
I/O
21
I/O
22
I/O
23
I/O
24
I/O
25
I/O
26
I/O
27
I/O
28
I/O
29
I/O
30
I/O
31
Y
0
Y
1
Y
2
Y
3
I/O
33
I/O
32
I/O
34
I/O
35
I/O
36
I/O
37
I/O
38
I/O
39
I/O
40
I/O
41
I/O
42
I/O
43
I/O
44
I/O
45
I/O
46
I/O
47
IN
4
IN 7
IN 6
I/O 63
I/O 62
I/O 61
I/O 60
I/O 59
I/O 58
I/O 57
I/O 56
I/O 55
I/O 54
I/O 53
I/O 52
I/O 51
I/O 50
I/O 49
I/O 48
I/O 0
I/O 1
I/O 2
I/O 3
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
TDI
TDO
TMS
TCK
I/O 4
I/O 5
VCCIO
RESET
Input Bus
lnput
Bus
0139F/1048EA
IN
8
GOE 0
GOE 1
IN 2