Fast Models Reference Manual - ARM Information Center

Peripheral and Interface Components
Figure 5-60 on page 5-136 shows a view of the component in System Canvas.
This component is written in LISA+.
Figure 5-61 MessageBox component in System Canvas
Ports
Table 5-113 provides a brief description of the MessageBox component ports.
Name Port protocol Type Description
Table 5-113 MessageBox ports
pvbus_s PVBus Slave Provides memory mapped access to the
MessageBox registers and shared buffer.
message MessageBox Slave Delivers messages to the parent
component, and receives messages from
the parent for delivery to the target
driver.
intr Signal Master Optional interrupt line used to indicate
availability of incoming message data.
Alternatively the status register can be
polled.
MessageBox
The MessageBox component has one additional protocol.
The message port implements half of a protocol for communication with a parent device. The
other half is implemented by the parent device. When the CONTROL register is written to with
the MBOX_CONTROL_END value, the data between the START and END offsets in the
buffer are sent by reference to the parent device. Either during this call, or afterwards, the parent
device is free to invoke the other message behaviors to set up an incoming packet and set the
RXREADY signal.
The protocol behaviors are:
begin_msg(void** buffer, uint32_t len)
Returns a pointer to the buffer for sending a message. len is ignored.
end_msg(uint32_t len)
Sets the START/END registers to indicate the start and end of the message in the
buffer and sets the RXREADY signal.
message(const void* buffer, uint32_t len)
Indicates that a message has been received, and the contents are in the buffer with
a length of len bytes. This behavior must be implemented by the parent device.
cancel_msg()
Cancel a message.
ARM DUI 0423J Copyright © 2008-2011 ARM. All rights reserved. 5-138
ID051811
Non-Confidential