MemoryMappedIO

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com.cmpware.cmp.mmio
Class MemoryMappedIO

java.lang.Object
  com.cmpware.cmp.mmio.MemoryMappedIO

All Implemented Interfaces:: ReadWriteInterface

public class MemoryMappedIO
extends java.lang.Object
implements ReadWriteInterface
extends java.lang.Object
implements ReadWriteInterface

This class implements the memory mapped IO. Here, registers or devices may be mapped to arbitrary addresses outside of the normal memory range.

This class has been changed to support the standard Memory interface, in addition to the send() and recv(). This only impacts the internal use of this class and should not change the way Link models are implemented.

Author:: SAG

Field Summary
`static java.lang.String`	`copyright` Copyright string

Constructor Summary
`MemoryMappedIO()`

Method Summary
`void`	`addInput(int addr, MemoryMappedIOReader mmior)` This method adds a Memory Mapped IO Reader interface to the memory mapped IO.
`void`	`addOutput(int addr, MemoryMappedIOWriter mmiow)` This method adds a Memory Mapped IO Writer interface to the memory mapped IO.
`static void`	`commit()` Since all writes should be shadowed in the Memory Mapped IO output ports, they must all be committed at the end of a simulation cycle.
`java.lang.String`	`dumpPorts()` This method prints status information about the Memory Mapped IO registers.
`MemoryMappedIOReader[]`	`getInputPorts()` This method returns an array of Memory Mapped IO Readers currently used as input ports.
`MemoryMappedIOWriter[]`	`getOutputPorts()` This method returns an array of Memory Mapped IO Writers currently used as output ports.
`boolean`	`isReadable(int addr)` This method returns true if the current address is readable and false otherwise.
`boolean`	`isValidAddress(int addr)`
`boolean`	`isWriteable(int addr)` This method returns true if the current address is writeable and false otherwise.
`byte`	`read(int addr)` This method returns a byte from the memory at address 'addr'.
`short`	`read16(int addr)` This method returns a 16-bit short from the memory at address 'addr'.
`int`	`read24(int addr)` This method returns a 24-bit unsigned integer from the memory at address 'addr'.
`int`	`read32(int addr)` This method returns a 32-bit int from the memory at address 'addr'.
`long`	`read64(int addr)` This method returns a 64-bit long from the memory at address 'addr'.
`int`	`recv(int addr)` This method reads the memory mapped IO from a specified address.
`void`	`send(int addr, int val)` This method writes the memory mapped IO at a specified address.
`void`	`write(int addr, byte data)` This method copies a byte from 'a' into the memory at address 'addr'.
`void`	`write16(int addr, short a)` This method writes the 16-bit value 'a' to the requested memory address.
`void`	`write24(int addr, int a)` This method writes a 24-bit value 'a' to the requested memory address.
`void`	`write32(int addr, int a)` This method writes the 32-bit value 'a' to the requested memory address.
`void`	`write64(int addr, long a)` This method writes the 64-bit value 'a' to the requested memory address.

Methods inherited from class java.lang.Object
`clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait`

Field Detail

copyright

public static final java.lang.String copyright

See Also:: Constant Field Values

Constructor Detail

MemoryMappedIO

public MemoryMappedIO()

Method Detail

addInput

public void addInput(int addr,
                     MemoryMappedIOReader mmior)

This method adds a Memory Mapped IO Reader interface to the memory mapped IO. If a Memory Mapped IO Reader already exists at this address, it is replaced.

Parameters:: addr - the address of the Memory Mapped IO Input port.; mmior - The Memory Mapped IO reader.

addOutput

public void addOutput(int addr,
                      MemoryMappedIOWriter mmiow)

This method adds a Memory Mapped IO Writer interface to the memory mapped IO. If a Memory Mapped IO Writer already exists at this address, it is replaced.

Parameters:: addr - the address of the Memory Mapped IO Output port.; mmiow - The Memroy Mapped IO writer.

recv

public int recv(int addr)
         throws MemoryAccessException

This method reads the memory mapped IO from a specified address.

Parameters:: addr - The address to be read.
Returns:: This method returns the memory mapped IO from a specified address.
Throws:: MemoryAccessException - if no shared register exists at this address.

send

public void send(int addr,
                 int val)
          throws MemoryAccessException

This method writes the memory mapped IO at a specified address.

Parameters:: addr - The address to be written.; val - The value to be written.
Throws:: MemoryAccessException - if no shared register exists at this address or if the write is an attempt to overwrite the shared register.

commit

public static void commit()

Since all writes should be shadowed in the Memory Mapped IO output ports, they must all be committed at the end of a simulation cycle. The method takes the lists of Memory Mapped IO ports read and written since the last commit() and committs them. Note this this method is static and will commit *all* memory mapped IO reads and writes from all users of this class.

getInputPorts

public MemoryMappedIOReader[] getInputPorts()

This method returns an array of Memory Mapped IO Readers currently used as input ports.

Returns:: This method returns an array of Memory Mapped IO Readers currently used as input ports.

getOutputPorts

public MemoryMappedIOWriter[] getOutputPorts()

This method returns an array of Memory Mapped IO Writers currently used as output ports.

Returns:: This method returns an array of Memory Mapped IO Writers currently used as output ports.