98
Lucent Technologies Inc.
Preliminary Data Sheet, Rev. 1
ORCA Series 3 FPGAs
September 1998
Timing Characteristics
Description
To define speed grades, the
ORCA Series part number
designation (see Ordering Information) uses a single-
digit number to designate a speed grade. This number
is not related to any single ac parameter. Higher num-
bers indicate a faster set of timing parameters. The
actual speed sorting is based on testing the delay in a
path consisting of an input buffer, combinatorial delay
through all PLCs in a row, and an output buffer. Other
tests are then done to verify other delay parameters,
such as routing delays, setup times to FFs, etc.
The most accurate timing characteristics are reported
by the timing analyzer in the
ORCA Foundry Develop-
ment System. A timing report provided by the develop-
ment system after layout divides path delays into logic
and routing delays. The timing analyzer can also pro-
vide logic delays prior to layout. While this allows rout-
ing budget estimates, there is wide variance in routing
delays associated with different layouts.
The logic timing parameters noted in the Electrical
Characteristics section of this data sheet are the same
as those in the design tools. In the PFU timing given in
Tables 40—47, symbol names are generally a concate-
nation of the PFU operating mode (as defined in
Table 3) and the parameter type. The setup, hold, and
propagation delay parameters, defined below, are des-
ignated in the symbol name by the SET, HLD, and DEL
characters, respectively.
The values given for the parameters are the same as
those used during production testing and speed bin-
ning of the devices. The junction temperature and sup-
ply voltage used to characterize the devices are listed
in the delay tables. Actual delays at nominal tempera-
ture and voltage for best-case processes can be much
better than the values given.
It should be noted that the junction temperature used in
the tables is generally 85 °C. The junction temperature
for the FPGA depends on the power dissipated by the
device, the package thermal characteristics (
ΘJA), and
the ambient temperature, as calculated in the following
equation and as discussed further in the Package
Thermal Characteristics section:
TJmax = TAmax + (P
ΘJA) °C
Note: The user must determine this junction tempera-
ture to see if the delays from
ORCA Foundry
should be derated based on the following derat-
ing tables.
Tables 38A and 38B provide approximate power supply
and junction temperature derating for OR3Cxx com-
mercial and industrial devices.
Table 39 provides the
same information for the OR3Txxx devices (both com-
mercial and industrial). The delay values in this data
sheet and reported by
ORCA Foundry are shown as
1.00 in the tables. The method for determining the
maximum junction temperature is defined in the Pack-
age Thermal Characteristics section. Taken cumula-
tively, the range of parameter values for best-case vs.
worst-case processing, supply voltage, and junction
temperature can approach 3 to 1.
Note: The derating tables shown above are for a typical critical path
that contains 33% logic delay and 66% routing delay. Since the
routing delay derates at a higher rate than the logic delay, paths
with more than 66% routing delay will derate at a higher rate
than shown in the table. The approximate derating values vs.
temperature are 0.26% per °C for logic delay and 0.45% per °C
for routing delay. The approximate derating values vs. voltage
are 0.13% per mV for both logic and routing delays at 25 °C.
Table 38A. Derating for Commercial Devices
(OR3Cxx)
TJ
(°C)
Power Supply Voltage
4.75 V
5.0 V
5.25 V
0
0.81
0.79
0.77
25
0.85
0.83
0.81
85
1.00
0.97
0.95
100
1.05
1.02
1.00
125
1.12
1.09
1.07
Table 38B. Derating for Industrial Devices
(OR3Cxx)
TJ
(°C)
Power Supply Voltage
4.5 V
4.75 V
5.0 V
5.25 V
5.5 V
–40
0.71
0.70
0.68
0.66
0.65
0
0.80
0.78
0.76
0.74
0.73
25
0.84
0.82
0.80
0.78
0.77
85
1.00
0.97
0.94
0.93
0.91
100
1.05
1.01
0.99
0.97
0.95
125
1.12
1.09
1.06
1.04
1.02
Table 39. Derating for Commercial/Industrial
Devices (OR3Txxx)
TJ
(°C)
Power Supply Voltage
3.0 V
3.3 V
3.6 V
–40
0.73
0.66
0.61
0
0.82
0.73
0.68
25
0.87
0.78
0.72
85
1.00
0.90
0.83
100
1.04
0.94
0.87
125
1.10
1.00
0.92