A1460A-1PQ208C Actel, A1460A-1PQ208C Datasheet - Page 10

• Manufacturer Part Number: A1460A-1PQ208C
• Description: FPGA ACT 3 Family 6K Gates 848 Cells 125MHz 0.8um (CMOS) Technology 5V 208-Pin PQFP
• Manufacturer: Actel

Specifications of A1460A-1PQ208C

• Package: 208PQFP
• Family Name: ACT 3
• Device Logic Gates: 6000
• Device Logic Units: 848
• Device System Gates: 15000
• Number Of Registers: 768
• Maximum Internal Frequency: 125 MHz
• Typical Operating Supply Voltage: 5 V
• Maximum Number Of User I/os: 167
• Maximum Propagation Delay Time: 2.6 ns

Figure 5 • Function Diagram for I/O Pad Driver
Routed Clocks
The routed clock networks are referred to as CLK0 and CLK1.
Each network is connected to a clock module (CLKMOD)
that selects the source of the clock signal and may be driven
as follows (see Figure 6):
• externally from the CLKA pad
• externally from the CLKB pad
• internally from the CLKINA input
• internally from the CLKINB input
The clock modules are located in the top row of I/O modules.
Clock drivers and a dedicated horizontal clock track are
located in each horizontal routing channel. The function of
the clock module is determined by the selection of clock
macros from the macro library. The macro CLKBUF is used to
connect one of the two external clock pins to a clock network,
and the macro CLKINT is used to connect an internally
generated clock signal to a clock network. Since both clock
networks are identical, the user does not care whether CLK0
or CLK1 is being used. Routed clocks can also be used to drive
high fanout nets like resets, output enables, or data enables.
This saves logic modules and results in performance
increases in some cases.
1-184
DATAOUT
DATAIN
SLEW
IEN
OE
INEN
OUTEN
PAD
Figure 6 • Clock Networks
Ro uting Str uctur e
The ACT 3 architecture uses vertical and horizontal routing
tracks to connect the various logic and I/O modules. These
routing tracks are metal interconnects that may either be of
continuous length or broken into segments. Segments can be
joined together at the ends using antifuses to increase their
lengths up to the full length of the track.
Horizontal Routing
Horizontal channels are located between the rows of modules
and are composed of several routing tracks. The horizontal
routing tracks within the channel are divided into one or
more segments. The minimum horizontal segment length is
the width of a module-pair, and the maximum horizontal
segment length is the full length of the channel. Any segment
that spans more than one-third the row length is considered a
long horizontal segment. A typical channel is shown in
Figure 7. Undedicated horizontal routing tracks are used to
route signal nets. Dedicated routing tracks are used for the
global clock networks and for power and ground tie-off tracks.
Vertical Routing
Other tracks run vertically through the modules. Vertical
tracks are of three types: input, output, and long. Vertical
tracks are also divided into one or more segments. Each
segment in an input track is dedicated to the input of a
particular module. Each segment in an output track is
dedicated to the output of a particular module. Long
segments are uncommitted and can be assigned during
FROM
PADS
CLKB
CLKA
DRIVERS
CLOCK
CLKMOD
CLKINB
CLKINA
CLOCK TRACKS
S0
S1
CLKO(17)
CLKO(16)
CLKO(15)
CLKO(2)
CLKO(1)
INTERNAL
SIGNAL