Preliminary
Architecture
www.ti.com
3.2.5.4
Transmit Buffer Descriptor Format
A transmit (TX) buffer descriptor (
) is a contiguous block of four 32-bit data words aligned on a
32-bit boundary that describes a packet or a packet fragment.
shows the transmit buffer
descriptor described by a C structure.
Figure 3-6. Transmit Buffer Descriptor Format
Word 0
31
0
Next Descriptor Pointer
Word 1
31
0
Buffer Pointer
Word 2
31
16 15
0
Buffer Offset
Buffer Length
Word 3
31
30
29
28
27
26
25
16
SOP
EOP
OWNER
EOQ
TDOWNCMPLT
PASSCRC
Reserved
15
0
Packet Length
Example 3-1. Transmit Buffer Descriptor in C Structure Format
/*
// EMAC Descriptor
//
// The following is the format of a single buffer descriptor
// on the EMAC.
*/
typedef struct _EMAC_Desc {
struct _EMAC_Desc *pNext; /* Pointer to next descriptor in chain */
Uint8 *pBuffer; /* Pointer to data buffer */
Uint32 BufOffLen; /* Buffer Offset(MSW) and Length(LSW) */
Uint32 PktFlgLen; /* Packet Flags(MSW) and Length(LSW) */
} EMAC_Desc;
/* Packet Flags */
#define EMAC_DSC_FLAG_SOP 0x80000000u
#define EMAC_DSC_FLAG_EOP 0x40000000u
#define EMAC_DSC_FLAG_OWNER 0x20000000u
#define EMAC_DSC_FLAG_EOQ 0x10000000u
#define EMAC_DSC_FLAG_TDOWNCMPLT 0x08000000u
#define EMAC_DSC_FLAG_PASSCRC 0x04000000u
418
EMAC/MDIO Module
SPRUGX9 – 15 April 2011
© 2011, Texas Instruments Incorporated
Содержание TMS320C6A816 Series
Страница 2: ...Preliminary 2 SPRUGX9 15 April 2011 Submit Documentation Feedback 2011 Texas Instruments Incorporated...
Страница 92: ...92 Read This First SPRUGX9 15 April 2011 Submit Documentation Feedback 2011 Texas Instruments Incorporated...
Страница 1122: ...1122 Multichannel Audio Serial Port McASP SPRUGX9 15 April 2011 Submit Documentation Feedback 2011 Texas Instruments Incorporated...
Страница 1562: ...1562 Real Time Clock RTC SPRUGX9 15 April 2011 Submit Documentation Feedback 2011 Texas Instruments Incorporated...
Страница 1658: ...1658 Timers SPRUGX9 15 April 2011 Submit Documentation Feedback 2011 Texas Instruments Incorporated...
Страница 1750: ...1750 UART IrDA CIR Module SPRUGX9 15 April 2011 Submit Documentation Feedback 2011 Texas Instruments Incorporated...
Страница 1984: ...1984 Universal Serial Bus USB SPRUGX9 15 April 2011 Submit Documentation Feedback 2011 Texas Instruments Incorporated...