TMS320F28004x microcontroller configurable logic block input and output

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TMS320F28004x microcontroller configurable logic block input and output [Copy link]

The 2000 Configurable Logic Block (CLB) is a collection of configurable blocks that can be interconnected using software to implement custom digital logic functions. The CLB is able to enhance existing peripherals such as ePWM, eCAP, eQEP through a set of X-bar connections. The X-bar also allows the CLB to be connected to external GPIO pins, in this way, the CLB can be configured to interact with peripherals to perform small logic functions, such as a simple PWM generator, or implement a custom serial data exchange protocol.

Support documentation is available at: C:\ti\c2000\C2000Ware_3_01_00_00\utilities\clb_tool\clb_syscfg\doc

280049C has 4 configurable instances.

Inputs
Each CLB instance sees a common set of 72 input signals, called global input signals. In addition, each CLB instance has a specific set of 25 input signals that are unique to each instance, called local input signals. Each of the eight inputs to the CLB can choose from either global input signals or local input signals. See the table below for details

In order to use GPIOs as inputs to a CLB, the user must use input X-BARs and CLB X-BARs.

The 8 outputs of the output
CLB are replicated as 16 output signals. Each of these 16 outputs has an individual enable bit defined in the CLB output enable register, CLB_OUT_EN_REG. The CLB outputs go to the ePWM, eCAP, eQEP, and X-bar in the device. This allows the user to enhance the functionality of these modules.

The CLB Tile
The purpose of the CLB tile is to provide the CLB logic reconfiguration capability. The CLB tile contains the following submodules:

Counter: The Counter submodule can be configured as an adder, counter, or shifter. When used as an adder, it can add or subtract. When used as a counter, it can count up or down. When used as a shifter, it can shift left or right. The counter event input and reset input can be freely connected to any other submodule in the same instance. There are three counters on each block instance.
LUT4: The LUT4 submodule has a 4-input lookup table function and is able to implement arbitrary Boolean equations with up to 4 inputs. There are three LUT4 submodules in each CLB instance.
FSM: The Finite State Machine (FSM) submodule can be configured as a single four-state finite state machine or as two independent two-state finite state machines. The FSM accepts two external inputs and generates two state outputs and one combinational output. When not used as a state machine, the FSM submodule can accept two external inputs and work as a 4-input LUT. There are three FSM submodules in each CLB instance.
Output LUT: The output LUT is a three-input lookup table submodule that is able to implement arbitrary combinational Boolean equations with up to three inputs. There are eight such blocks in a CLB tile, each associated with one of the tile outputs.
High Level Controller: The High Level Controller (HLC) submodule is an event-driven block that can handle up to four concurrent events. An event can be activity on any other block output. When each event occurs, a set of predefined actions are performed. The HLC also provides data exchange and interrupt mechanisms for the CPU subsystem. There are four working registers (R0, R1, R2, and R3) that can be used for basic operations and to modify or set the values of the three counter blocks. Unlike the other submodules, there is only one HLC in each tile.
Configurable Switch Block: The configurable switch block provides dynamic connections between all the blocks listed above. The submodules can be connected by the user, the only restriction is that they cannot form a loop in the tile. The
CLB tile consists of three sets of counter blocks, FSM and LUT4, a high level controller, and eight output LUT blocks, as shown in the following figure: