USE ULTRA37000™ FOR
ALL NEW DESIGNS CY7C341B
Document #: 38-03016 Rev. *C Page 4 of 12
Logic Array Blocks
There are 12 logic arra y blocks in the CY7C341B. Each LAB
consists of a macrocell array containing 16 macrocells, an
expander product term array containing 32 expanders, and an
I/O block. The LAB is fed by the programmable interconnect
array and the dedicated input bus. All macrocell feedbacks go
to the macrocell array, the expander array, and the program-
mable interconnect array . Expanders feed themselves and the
macrocell array. All I/O feedbacks go to the programmable
interconnect array so that they may be accessed by macro-
cells in other LABs as well as the macrocells in the LAB in
which they are situated.
Externally, the CY7C341B provides eight dedicated inputs,
one of which may be used as a system clock. There are 64 I/O
pins that may be individually configured for input, output, or
bidirectional data flow.
Programmable Interconnect Array
The Programmable Interconnect Array (PIA) solves inter-
connect limitations by routing only the signals needed by each
logic array block. The inputs to the PIA are the outputs of every
macrocell within the device and the I/O pi n fe edback of eve ry
pin on the device.
Unlike masked or programmable gate arrays, which induce
variable delay dependent on routing, the PIA has a fixed delay .
This eliminates undesired skews among logic signals, which
may cause glitches in internal or external logic. The fixed
delay, regardless of programmable interconnect a rray config-
uration, simplifies design by assuring that internal signal
skews or races are avoided. The result is ease of design imple-
mentation, often in a single pass, without the mu ltiple internal
logic placement and routing iterations required for a program-
mable gate array to achieve design timing objectives.
Design Recommendations
For proper operation, input and output pins must be
constrained to the range GND < (VIN or VOUT) < VCC.
Unused inputs must always be tied to an appropriate logic
level (either VCC or GND). Each set of VCC and GND pins
must be connected together directly at the device. Power
supply decoupling capacitors of at least 0.2 mF must be
connected between VCC and GND. For the most effective
decoupling, each VCC pin should be separately decoupled to
GND, directly at the device. Decoupling capacitors should
have good frequency response, such as monolithic ceramic
types.
Design Security
The CY7C341B contains a programmable design security
feature that controls th e access to the data programmed into
the device. If this programmable feature is used, a proprietary
design implemented in the device cannot be copied or
retrieved. This enables a high level of design control to be
obtained since programmed data within EPROM cells is
invisible. The bit that controls this function, along with all other
program data, may be reset simply by erasing the device.
The CY7C341B is fully functionally tested and guaranteed
through complete testing of each programmable EPROM bit
and all internal logic elements thus ensuring 100%
programming yield.
The erasable nature of these devices allows test programs to
be used and erased during early stages of the production flow .
The devices also contain on-board l ogic test circuitry to a llow
verification of function and AC specification once encapsu-
lated in non-windowed packages.
400
300
200
100
1 kHz 10 kHz 100 kHz 1 MHz
ICC
MAXIMUM FREQUENCY
10 MHz
050 MHz100 Hz
ACTIVE (mA) Typ.
VCC = 5.0V
Room Temp.
Typical ICC vs. fMAX
01 2 3 4
I OUTPUT CURRENT (mA) TYPICAL
V
O
OUTPUTVOLTAGE (V)
250
200
150
100
50
5
O
I
OH
I
OL
V
CC
= 5.0V
Room Temp.
Output Drive Current