Intel
®
IXP400 Digital Signal Processing (DSP) Software Version 2.5
Message Format and Delivery Mechanism
API Reference Manual
21
4.2
Message Header Format
Return
•
XSUCC
— If successful
•
XERROR
— If errors
Caution
Message buffer requires 4-byte alignment.
Note
The message buffer can be used for any other purpose, after posting.
Format
typedef struct{
UINT32
transactionId; /* used by apps to track the message */
UINT16
instance;
/* instance ID (1-0xffff), 0:reserved */
UINT8
resource;
/* MPR resource type */
UINT8
reserved;
/* reserved for future */
UINT16
size;
/* total size in bytes */
UINT8
type;
/* message type */
UINT8
attribute;
/* attribute, reserved for future */
} XMsgHdr_t, *XMsgRef_t_t;
Caution
Message content must follow the header in contiguous memory.
Macros
#define XMSG_MAKE_HEAD(pMsg, trans, res, inst, sz, typ, attr) \
((XMsgRef_t)(pMsg))->transactionId = trans;\
((XMsgRef_t)(pMsg))->instance = inst;\
((XMsgRef_t)(pMsg))->resource = res;\
((XMsgRef_t)(pMsg))->reserved = 0;\
((XMsgRef_t)(pMsg))->size = sz;\
((XMsgRef_t)(pMsg))->type = typ;\
((XMsgRef_t)(pMsg))->attribute = attr;
XStatus_t xMsgWrite (void *pMsgBuf); (Sheet 2 of 2)
