MPC8540 datasheet(666/1302 Pages) FREESCALE

666 / 1302 page

MPC8540 PowerQUICC III Integrated Host Processor Reference Manual, Rev. 1

14-40

Freescale Semiconductor

Three-Speed Ethernet Controllers

14.5.3.3.9 Out-of-Sequence Tx Data Buffer Pointer Register (OSTBDP)

The out-of-sequence Tx data buffer pointer register (OSTBDP), shown in Figure 14-26, contains

the data buffer pointer fields in the same format as a regular TxBD. With OSTBD, it provides the

complete 8-byte descriptor. This area must be cleared while not in use.

Table 14-24 describes OSTBDP.

14.5.3.4 TSEC Receive Control and Status Registers

This section describes the control and status registers that are used specifically for receiving

Ethernet frames. All of the registers are 32 bits wide.

10–13

Retry count. Written by TSEC.

0 The frame is sent correctly the first time.

1 More than zero attempts were needed to send the transmit frame. If this field is 15, 15 or more

retries were needed. The Ethernet controller updates RC after sending the buffer.

Underrun. Written by TSEC.

0 No underrun encountered (data was retrieved from external memory in time to send a complete

frame).

1 The Ethernet controller encountered a transmitter underrun condition while sending the

associated buffer. The TSEC terminates the transmission and updates UN.

—

Reserved

16–31

OSTBDLEN

Out-of-sequence TxBD data length. Written by user. Data length is the number of octets the TSEC

transmits from this BD’s data buffer. It is never modified by the TSEC. This field must be greater

than zero in order for a transfer to take place.

OSTBDP

Reset

0000_0000_0000_0000_0000_0000_0000_0000

Offset

TSEC1:0x2_42B4; TSEC2:0x2_52B4

Figure 14-26. OSTBDP Register Definition

Table 14-24. OSTBDP Field Descriptions

Bits

Name

Description

0–31

OSTDBP

Out-of-sequence Tx Data Buffer Pointer. Written by user. The transmit data buffer pointer contains

the address of the associated data buffer. There are no alignment requirements for this address.

Table 14-23. OSTBD Field Descriptions (continued)

Bits

Name

Description

MPC8540 Datasheet(PDF) 666 Page - Freescale Semiconductor, Inc

MPC8540 Datasheet(HTML) 666 Page - Freescale Semiconductor, Inc

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 ...More

Datasheet Download

Link URL