HC4GX15 Datasheet, PDF (27/668 Pages) Altera Corporation – HardCopy IV Device Handbook

HIV51002-1.0
2. Logic Array Block and Adaptive Logic
Module Implementation in HardCopy IV
Devices
This chapter describes how the Stratix^® IV’s logic array blocks (LABs) and memory
logic array blocks (MLABs) are implemented in a HardCopy^® IV device. In Stratix IV
devices, the core fabric consists of an array of LABs and MLABs. LABs and MLABs
are composed of adaptive logic modules (ALMs) that are configurable and can
implement various logic, arithmetic, and register functions of a customer design. In
addition, MLABs can implement memory functions. By comparison, the core fabric in
HardCopy IV devices are built using an array of flexible, fine-grain architecture
blocks called HCells that can efficiently implement all the functionality of the ALMs,
LABs, and MLABs. HardCopy IV devices offer improved performance and significant
static power savings compared to Stratix IV FPGA prototype devices because only the
HCells required to implement the customer design are used, while the unused HCells
are powered down.
f For more information about ALMs, LABs, and MLABs, refer to the Logic Array Blocks
and Adaptive Logic Modules in Stratix IV Devices chapter in volume 1 of the Stratix IV
Device Handbook.
This chapter contains the following sections:
■ “HCells”
■ “ALM and LAB Function Implementation” on page 2–2
■ “MLAB Function Implementation” on page 2–4
HCells
HCells are a collection of logic transistors based on 0.9-V, 40-nm process technology.
The construction of logic using HCells allows flexible functionality such that when
HCells are combined, all viable logic combinations of Stratix IV functionality are
replicated. These HCells constitute the array of the HCell area, as shown in
Figure 2–1. Only the HCells needed to implement the design are assembled together,
which optimizes HCell used. The unused area of the HCell logic fabric is powered
down, resulting in significant static power savings compared with the Stratix IV
FPGA prototype.
© December 2008 Altera Corporation
HardCopy IV Device Handbook, Volume 1