Commercial/
Industrial
PEEL™ 22CV10A -7/-10/-15/-25
CMOS Programmable Electrically Erasable Logic Device
Features
s
High Speed/Low Power
- Speeds ranging from 7ns to 25ns
- Power as low as 30mA at 25MHz
Electrically Erasable Technology
- Superior factory testing
- Reprogrammable in plastic package
- Reduces retrofit and development costs
s
s
Architectural Flexibility
- 132 product term X 44 input AND array
- Up to 22 inputs and 10 outputs
- Up to 12 configurations per macrocell
- Synchronous preset, asynchronous clear
- Independent output enables
- 24-pin DIP/SOIC/TSSOP and 28-pin PLCC
Application Versatility
- Replaces random logic
- Pin and JEDEC compatible with 22V10
- Enhanced Architecture fits more logic
than ordinary PLDs
s
s
Development/Programmer Support
- Third party software and programmers
- ICT PLACE Development Software
General Description
The PEEL™22CV10A is a Programmable Electrically Eras-
able Logic (PEEL™) device providing an attractive alterna-
tive to ordinary PLDs. The PEEL™22CV10A offers the
performance, flexibility, ease of design and production
practicality needed by logic designers today. The
PEEL™22CV10A is available in 24-pin DIP, SOIC, TSSOP
and 28-pin PLCC packages (see Figure 1), with speeds
ranging from 7ns to 25ns and with power consumption as
low as 30mA. EE-reprogrammability provides the conve-
nience of instant reprogramming for development and a
reusable production inventory, minimizing the impact of
programming changes or errors. EE-reprogrammability
also improves factory testability, thus ensuring the highest
quality possible. The PEEL™22CV10A is JEDEC file com-
patible with standard 22V10 PLDs. Eight additional configu-
rations per macrocell (a total of 12) are also available by
using the “+” software/programming option (i.e.,
22CV10A+). The additional macrocell configurations allow
more logic to be put into every design. Programming and
development support for the PEEL™22CV10A are pro-
vided by popular third-party programmers and develop-
ment software. ICT also offers free PLACE development
software.
Figure 1. Pin Configuration
I/CLK
I
I
I
I
I
I
I
I
I
I
GND
1
2
3
4
5
6
7
8
9
10
11
12
24
23
22
21
20
19
18
17
16
15
14
13
VCC
I/O
I/O
I/O
I/O
I/O
I/O
I/O
I/O
I/O
I/O
I
Figure 2. Block Diagram
DIP
TSSOP
PLCC
*Optional extra ground pin for
-7/I-7 speed grade.
SOIC
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PEEL
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22CV10A
Function Description
The PEEL™22CV10A implements logic functions as sum-
of-products expressions in a programmable-AND/ fixed-OR
logic array. User-defined functions are created by program-
ming the connections of input signals into the array. User-
configurable output structures in the form of I/O macrocells
further increase logic flexibility.
programming selected connections in the AND array. (Note
that PEEL™ device programmers automatically program
the connections on unused product terms so that they will
have no effect on the output function.)
Variable Product Term Distribution
The PEEL™22CV10A provides 120 product terms to drive
the 10 OR functions. These product terms are distributed
among the outputs in groups of 8, 10, 12, 14 and 16 to form
logical sums (see Figure 3). This distribution allows opti-
mum use of device re-sources.
Architecture Overview
The PEEL™22CV10A architecture is illustrated in the block
diagram of Figure 2. Twelve dedicated inputs and 10 I/Os
provide up to 22 inputs and 10 outputs for creation of logic
functions. At the core of the device is a programmable elec-
trically-erasable AND array which drives a fixed OR array.
With this structure, the PEEL™22CV10A can implement up
to 10 sum-of-products logic expressions.
Associated with each of the 10 OR functions is an I/O mac-
rocell which can be independently programmed to one of 4
different configurations. The programmable macrocells
allow each I/O to create sequential or combinatorial logic
functions with either active-high or active-low polarity.
Programmable I/O Macrocell
The output macrocell provides complete control over the
architecture of each output. The ability to configure each
output independently permits users to tailor the configura-
tion of the PEEL™22CV10A to the precise requirements of
their designs.
Macrocell Architecture
Each I/O macrocell, as shown in Figure 4, consists of a D-
type flip-flop and two signal-select multiplexers. The config-
uration of each macrocell is determined by the two
EEPROM bits controlling these multiplexers (refer to Table
1). These bits determine output polarity and output type
(registered or non-registered). Equivalent circuits for the
four macro-cell configurations are illustrated in Figure 5.
AND/OR Logic Array
The programmable AND array of the PEEL™22CV10A
(shown in Figure 3) is formed by input lines intersecting
product terms. The input lines and product terms are used
as follows:
44 Input Lines:
24 input lines carry the true and complement
of the signals applied to the 12 input pins
20 additional lines carry the true and complement
values of feedback or input signals from
the 10 I/Os
132 product terms:
120 product terms (arranged in 2 groups of 8,
10, 12, 14 and 16) used to form logical sums
10 output enable terms (one for each I/O)
1 global synchronous present term
1 global asynchronous clear term
At each input-line/product-term intersection there is an
EEPROM memory cell which determines whether or not
there is a logical connection at that intersection. Each prod-
uct term is essentially a 44-input AND gate. A product term
which is connected to both the true and complement of an
input signal will always be FALSE, and thus will not affect
the OR function that it drives. When all the connections on
a product term are opened, a “don’t care” state exists and
that term will always be TRUE. When programming the
PEEL™22CV10A, the device programmer first performs a
bulk erase to remove the previous pattern. The erase cycle
opens every logical connection in the array. The device is
then configured to perform the user-defined function by
Output Type
The signal from the OR array can be fed directly to the out-
put pin (combinatorial function) or latched in the D-type flip-
flop (registered function). The D-type flip-flop latches data
on the rising edge of the clock and is controlled by the glo-
bal preset and clear terms. When the synchronous preset
term is satisfied, the Q output of the register will be set
HIGH at the next rising edge of the clock input. Satisfying
the asynchronous clear term will set Q LOW, regardless of
the clock state. If both terms are satisfied simultaneously,
the clear will override the preset.
Output Polarity
Each macrocell can be configured to implement active-high
or active-low logic. Programmable polarity eliminates the
need for external inverters.
Output Enable
The output of each I/O macrocell can be enabled or dis-
abled under the control of its associated programmable
output enable product term. When the logical conditions
programmed on the output enable term are satisfied, the
output signal is propagated to the I/O pin. Otherwise, the
output buffer is driven into the high-impedance state.
Under the control of the output enable term, the I/O pin can
function as a dedicated input, a dedicated output, or a bi-
directional I/O. Opening every connection on the output
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22CV10A
enable term will permanently enable the output buffer and
yield a dedicated output. Conversely, if every connection is
intact, the enable term will always be logically false and the
I/O will function as a dedicated input.
Design Security
The PEEL™22CV10A provides a special EEPROM secu-
rity bit that prevents unauthorized reading or copying of
designs programmed into the device. The security bit is set
by the PLD programmer, either at the conclusion of the pro-
gramming cycle or as a separate step after the device has
been programmed. Once the security bit is set, it is impos-
sible to verify (read) or program the PEEL™ until the entire
device has first been erased with the bulk-erase function.
Input/Feedback Select
When configuring an I/O macrocell to implement a regis-
tered function (configurations 1 and 2 in Figure 5), the Q
output of the flip-flop drives the feedback term. When con-
figuring an I/O macrocell to implement a combinatorial
function (configurations 3 and 4 in Figure 5), the feedback
signal is taken from the I/O pin. In this case, the pin can be
used as a dedicated input or a bi-directional I/O. (Refer
also to Table 1.)
Signature Word
The signature word feature allows a 24-bit code to be pro-
grammed
into
the
PEEL™22CV10A
if
the
PEEL™22CV10A+ software option is used. The code can
be read back even after the security bit has been set. The
signature word can be used to identify the pattern pro-
grammed into the device or to record the design revision,
etc.
Additional Macro Cell Configurations
Besides the standard four-configuration macrocell shown in
Figure 5, each PEEL™22CV10A provides an additional
eight configurations that can be used to increase design
flexibility. The configurations are the same as provided by
the PEEL™18CV8 and PEEL™22CV10AZ. However, to
maintain JEDEC file compatibility with standard 22V10
PLDs the additional configurations can only be utilized by
specifying the PEEL™22CV10A+ for logic assembly and
programming. To reference these additional configurations
please refer to the PEEL™22CV10A+ specifications at the
end of this data sheet.
Figure 4. Block Diagram of the PEEL™ 22CV10A I/O Macrocell.
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