Fast Models Reference Manual - ARM Information Center

Peripheral and Interface Components
PVDevice protocol
The PVDevice protocol enables you to implement support for memory-mapped device registers.
The two methods are called through the device port on the PVBusSlave, in order to handle bus
read/write transactions:
read(pv::ReadTransaction) : pv::Tx_Result
This method allows a device to handle a bus read transaction.
write(pv::WriteTransaction) : pv::Tx_Result
This method allows a device to handle a bus write transaction.
The C++ transaction and Tx_Result classes are described in further detail. See C++ classes on
page 5-15.
The PVDevice protocol uses two optional behaviors to differentiate between transaction
originating from the CPU (loads and stores) and transactions originating from an attached
debugger:
optional slave behavior debugRead(pv::ReadTransaction tx) : pv::Tx_Result
If implemented, this method enables the device to handle a debug read
transaction.
optional slave behavior debugWrite(pv::WriteTransaction tx) : pv::Tx_Result
If implemented, this method enables the device to handle a debug write
transaction.
If the debugRead and debugWrite behaviors are implemented, they are called for all debug
transactions. If they are not implemented, debug transactions are handled by the read and write
behaviors.
PVBusSlaveControl
setFillPattern(uint32_t fill1, uint32_t fill2)
This sets a two-word alternating fill pattern to be used by uninitialized memory.
setAccess(pv::bus_addr_t base, pv::bus_addr_t top, pv::accessType type, pv::accessMode
mode)
This reconfigures handling for a region of memory.
base (inclusive value) and top (exclusive value) specify the address range to
configure. Both base and top values must be 4KB page aligned.
type selects what types of bus access must be reconfigured. It can be one of:
• pv::ACCESSTYPE_READ
• pv::ACCESSTYPE_WRITE
• pv::ACCESSTYPE_RW
mode defines how bus accesses must be handled. See pv::accessMode values on
page 5-11.
*getReadStorage(pv::bus_addr_t address, pv::bus_addr_t *limit) : const uint8_t*
*getWriteStorage(pv::bus_addr_t address, pv::bus_addr_t *limit) : uint8_t *
These two methods allow you to access the underlying storage that PVBusSlave
allocates to implement a region of memory.
The return value is a pointer to the byte that represents the storage corresponding
to the address of base.
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