APBUART - APB UART

Table of Contents

• Overview
• Interface
• Example Instantiation

Overview

The APBUART model creates an UART device, which is mapped to a TCP port on the host system. The class inherits from the classes gs::reg::gr_device, APBDevice and CLKDevice. This model can be used as a serial console for exchanging data or printing debug information. The model has several registers which are listed in table 45. Further information can be found in GRLIB IP Core User’s Manual (chapter 16).

Table 45 - APBUART Registers

APB address offset	Register
0x0	UART Data register
0x4	UART Status register
0x8	UART Control register
0xC	UART Scaler register

Interface

The GRLIB VHDL model of the APBUART is configured using Generics. For the implementation of the TLM model most of these Generics were refactored to constructor parameters of class AHBUART. An overview about the available parameters is given in table 46.

Table 46 - APBUART Constructor Parameters

Parameter	Description
name	SystemC name of the module
backend	Selects the IO backend to be used, currently only TCP available
pindex	APB slave index
paddr	ADDR field of the APB BAR
pmask	MASK field of the APB BAR
pirq	Index of the interrupt line
console	Prints output from the UART on console during VHDL simulation and speeds up simulation by always returning ‘1’ for Data Ready bit of UART Status register. Does not effect synthesis.
powmon	Enable power monitoring

Example Instantiation

This example shows how to instantiate the module APBUART. In line 873 the constructor is called to create the new object. In line 882 the module is connected to the bus and in line 886 the clock is set. In line 884 the interrupts are connected via Signalkit.

APBUART *apbuart = new APBUART(sc_core::sc_gen_unique_name("apbuart", false), io,
  index,           // index
  addr,            // paddr
  mask,            // pmask
  irq,             // pirq
  p_report_power   // powmon
);

// Connecting APB Slave
apbctrl.apb(apbuart->bus);
// Connecting Interrupts
signalkit::connect(irqmp.irq_in, apbuart->irq, irq);
// Set clock
apbuart->set_clk(p_system_clock,SC_NS);