Sundance SMT6025 v.2.9 - Manual (Page 22)

Version 2.9 Page 22 of 45 SMT6025 User Manual
15.2 Command word
A command word is a 32-bit value transmitted from the DSP to the host by
means of mailbox 1 (see section 14). The value is interpreted as an
HSC_WORD containing the following fields:
typedef struct {
UINT32 Data :25; // Data value
UINT32 Fn : 4; // Function code
UINT32 Channel : 3; // Channel selector
} HSC_WORD;
• Channel
The high-speed-channel number.
• Fn
A code indicating the function the host is to perform.
Value Function
Description
0..1 Reserved
2 HSC_OpenHandler Open a handler
3 HSC_CloseHandler Close the current handler
4 HSC_CloseHostApp Close the host application
5 HSC_SramToHost Take SRAM data
6 HSC_HostToSram Give SRAM data
7 HSC_OpenPci Prepare for PCI memory transfers
8 HSC_ClosePci Terminate PCI memory transfers
9 HSC_PciToHost Write to PCI memory
10 HSC_HostToPci Read from PCI memory
11 HSC_UserDefined Perform user-defined function
11..15 Reserved
• Data field
A 25 bit unsigned value specific to the selected function.
User Manual (QCF42); Version 2.9, 22/02/02; © Sundance Multiprocessor Technology Ltd. 2002