iCE65L01F-LCB81C Lattice, iCE65L01F-LCB81C Datasheet - Page 9

• Manufacturer Part Number: iCE65L01F-LCB81C
• Description: FPGA - Field Programmable Gate Array iCE65 1280 LUTs, 1.0 1.2V Ultra Low-Power
• Manufacturer: Lattice

Specifications of iCE65L01F-LCB81C

• Rohs: yes
• Number Of Gates: 1280
• Number Of Logic Blocks: 16
• Number Of I/os: 63
• Maximum Operating Frequency: 256 MHz
• Operating Supply Voltage: 1.2 V
• Maximum Operating Temperature: + 70 C
• Mounting Style: SMD/SMT
• Package / Case: CBGA-81
• Distributed Ram: 64 Kbit
• Minimum Operating Temperature: 0 C
• Operating Supply Current: 12 uA
• Factory Pack Quantity: 490

Lattice Semiconductor Corporation
www.latticesemi.com
Implementing Subtracters, Decrementers
As mentioned earlier, the Carry Logic generates a High output whenever the sum of I1 + I2 + CARRY_IN
generates a carry. The Carry Logic does not specifically have a subtract mode. To implement a subtract function or
decrement function, logically invert either the I1 or I2 input and invert the initial carry input. This performs a 2s
complement subtract operation.
CARRY_IN
GND
GND
A[1]
B[1]
A[0]
B[0]
I0
I1
I2
I3
I0
I1
I2
I3
I0
I1
I2
I3
Figure 6: Two-bit Adder Example
Carry
Logic
Carry
Logic
LUT4
LUT4
LUT4
CARRY_OUT
SUM[1]
SUM[0]
(2.42, 30-MAR-2011)
9