xa2c32a Xilinx Corp., xa2c32a Datasheet - Page 3

• Manufacturer Part Number: xa2c32a
• Description: Coolrunner-ii Automotive Cpld Product Family
• Manufacturer: Xilinx Corp.

Figure 1
tion Blocks attach to pins and interconnect to each other
within the internal interconnect matrix. Each FB contains 16
Function Block
The CoolRunner-II Automotive CPLD Function Blocks con-
tain 16 macrocells, with 40 entry sites for signals to arrive
for logic creation and connection. The internal logic engine
is a 56 product term PLA. All Function Blocks, regardless of
the number contained in the device, are identical. For a
high-level view of the Function Block, see
DS315 (v1.1) October 31, 2006
Product Specification
I/O Pin
I/O Pin
I/O Pin
JTAG
shows the high-level architecture whereby Func-
R
40
Figure 2: Function Block
Set/Reset
PLA
BSC and ISP
Global
16
16
MC16
MC1
MC2
Global
Clocks
MC16
Figure 1: CoolRunner-II Automotive CPLD Architecture
MC1
MC2
3
16
Direct Inputs
DS090_02_101001
Function
Block 1
PLA
Out
To AIM
Figure
16 FB
2.
40
Clock and Control Signals
www.xilinx.com
BSC Path
AIM
macrocells. The BSC path is the JTAG Boundary Scan Con-
trol path. The BSC and ISP block has the JTAG controller
and In-System Programming Circuits.
At the high level, it is seen that the product terms (p-terms)
reside in a programmable logic array (PLA). This structure
is extremely flexible, and very robust when compared to
fixed or cascaded product term function blocks.
Classic CPLDs typically have a few product terms available
for a high-speed path to a given macrocell. They rely on
capturing unused p-terms from neighboring macrocells to
expand their product term tally, when needed. The result of
this architecture is a variable timing model and the possibil-
ity of stranding unusable logic within the FB.
The PLA is different — and better. First, any product term
can be attached to any OR gate inside the FB macrocell(s).
Second, any logic function can have as many p-terms as
needed attached to it within the FB, to an upper limit of 56.
Third, product terms can be re-used at multiple macrocell
OR functions so that within a FB, a particular logical product
need only be created once, but can be re-used up to 16
times within the FB. Naturally, this plays well with the fitting
software, which identifies product terms that can be shared.
The software places as many of those functions as it can
into FBs, so it happens for free. There is no need to force
macrocell functions to be adjacent or any other restriction
save residing in the same FB, which is handled by the soft-
ware. Functions need not share a common clock, common
set/reset or common output enable to take full advantage of
the PLA. Also, every product term arrives with the same
time delay incurred. There are no cascade time adders for
putting more product terms in the FB. When the FB product
16 FB
40
CoolRunner-II Automotive CPLD Product Family
Function
Block n
PLA
Direct Inputs
MC16
MC1
MC2
16
16
DS090_01_121201
I/O Pin
I/O Pin
I/O Pin
3