escc.hh

来自「一个mips虚拟机非常好代码,使用C++来编写的,希望大家多学学,」· HH 代码 · 共 88 行

#ifndef escc_hh_included
#define escc_hh_included

#include <clock.hh>
#include <checkpoint.hh>
#include <cpu.hh>
#include <device.hh>
#include <inttypes.hh>
#include <module.hh>
#include <sulima.hh>
#include <serial.hh>
#include <simarg.hh>
#include <ioqueue.hh>


class ZilogESCC
	: public Module, public Device, public Console, public IOListener
{
private:

    static SerialType<ZilogESCC> type;

    // The ESCC has two channels, and two external registers per channel
    enum Channel   { ChannelB = 0, ChannelA = 1 };
    enum Register  { Control  = 0, Data     = 1 };

    // Six main interrupt sources, from lowest to highest priority
    enum Interrupt { ExtIntrB = 0x01, TxIntrB = 0x02, RxIntrB = 0x04,
		     ExtIntrA = 0x08, TxIntrA = 0x10, RxIntrA = 0x20 };

    // Reported Interrupt Under Service codes for each source
    static const UInt8 intr_ius_map[];

    bool intr_enable;		// Master Interrupt Enable
    UInt8 intr_pending;		// Set of interrupts pending
    UInt8 intr_mask;		// Set of interrupts enabled
    UInt8 intr_vector;		// Interrupt vector
    UInt8 intr_ius;		// Interrupt Under Service

    static const UInt8 rx_fifo_mask = 7; // Bitmask for size of FIFO

    UInt8 rx_fifo[2][8];		// Receive FIFO
    UInt8 rx_hi[2];		// Next character to store
    UInt8 rx_lo[2];		// Next character to collect

    UInt8 reg;			// Internal register addressed

    unsigned int status_poll;	// Number of times SR polled since last write

    // Check if any interrupts are pending and signal CPU
    void check_interrupts(void);
	
    void setup_pty(void);

public:

    // Constructors, etc.
    ZilogESCC(const SimArgs& args);
    ZilogESCC(Checkpoint& cp);

    // Module interfaces.
    void reset(bool warm);

    // Serialization information.
    void checkpoint(Checkpoint& cp, bool parent = false) const;
    
    // Device access.
    ClockValue read(UInt64 addr, UInt64* buf, int size);
    ClockValue write(UInt64 addr, const UInt64* buf, int size);

    // Console
    void input(int c);
    void input(int c, int channel);

    void io_poll(void);

private:

    // Configuration data.
    struct {
	int irq;
	int debugirq;
    } conf;

};

#endif // escc_hh_included