Information

Enhanced Three-Speed Ethernet Controllers
MPC8308 PowerQUICC II Pro Processor Reference Manual, Rev. 1
Freescale Semiconductor 16-45
16.5.3.2.9 Transmit Descriptor Base Address Registers (TBASE0–TBASE7)
The TBASEn registers are written by the user with the base address of each TxBD ring n. Each such value
must be divisible by eight, since the three least significant bits always write as 000. Figure 16-19 describes
the definition for the TBASEn registers.
Table 16-24 describes the fields of the TBASEn registers.
16.5.3.2.10 Transmit Time Stamp Identification Register (TMR_TXTS1–2_ID)
Transmit time stamp identification register (TMR_TXTSn_ID). This register holds the identification
number of the transmitted frame corresponding to the timestamp captured in TMR_TXTSn_H/L. Each
time the eTSEC is instructed to capture the timestamp of an outgoing frame via TxFCB[PTP] the
associated field in TxFCB[PTP_ID] is stored in this register, overwriting the previous value.
This register is read only in normal operation. Figure 16-20 describes the definition for the
TMR_TXTSn_ID register.
Table 16-25 describes the fields of the TMR_TXTSn_ID register.
Offset eTSEC1:0x2_4204+8n; eTSEC2:0x2_5204+8n Access: Read/Write
0 28 29 31
R
TBASEn —
W
Reset All zeros
Figure 16-19. TBASE Register Definition
Table 16-24. TBASE0–TBASE7 Field Descriptions
Bits Name Description
0–28 TBASEn Transmit base for ring n. TBASE defines the starting location in the memory map for the eTSEC TxBDs. This
field must be 8-byte aligned. Together with setting the W (wrap) bit in the last BD, the user can select how many
BDs to allocate for the transmit packets. The user must initialize TBASE before enabling the eTSEC transmit
function on the associated ring.
29–31 — Reserved
Offset eTSEC1:0x2_4280+4n; eTSEC2:0x2_5280+4n Access: Read only
0151631
R
—
TXTS_ID
W
Reset All zeros
Figure 16-20. TMR_TXTSn_ID Register Definition
Table 16-25. TMR_TXTSn_ID Register Field Descriptions
Bits Name Description
0–15 — Reserved
16–31 TXTS_ID Tx time stamp identification field