MPC8540 datasheet(653/1302 Pages) FREESCALE

653 / 1302 page

Memory Map/Register Definition

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

Freescale Semiconductor

14-27

Table 14-8 describes the fields of the MINFLR register.

14.5.3.1.6 Pause Time Value Register (PTV)

PTV, shown in Figure 14-11, is written by the user to store the pause duration used when the TSEC

initiates a pause frame via TCTRL[TFC_PAUSE]. The low-order 16 bits (PT) represent the pause

time and the high-order 16 bits (PTE) represent the extended pause control parameter. The pause

time is measured in units of pause_quanta, equal to 512 bit times. The pause time can range from

0 to 65,535 pause_quanta, or 0 to 33,553,920 bit times. See Section 14.6.2.7, “Flow Control for

additional details.

Table 14-9 describes the fields of the PTV register.

Table 14-8. MINFLR Field Descriptions

Bits

Name

Description

0–24

—

Reserved

25–31

MINFLR Minimum receive frame length (typically 64 decimal). If the Ethernet receives an incoming frame

shorter than MINFLR, it discards that frame unless RCTRL[RSF] (receive short frames) is set, in

which case RxBD[SH] (frame too short) is set in the last RxBD. The largest allowable value for

MINFLR is 64. Unlike the MPC8260, in which PADs are added to make the transmit frame equal to

MINFLR bytes, if padding is requested, TSEC always PADS transmit frames to 64 bytes ignoring

MINFLR. MINFLR is only used to determine the minimum size of acceptable receive frames.

015 16

PTE

Reset

0000_0000_0000_0000_0000_0000_0000_0000

Offset

TSEC1:0x2_4028; TSEC2:0x2_5028

Figure 14-11. PTV Register Definition

Table 14-9. PTV Field Descriptions

Bits

Name

Description

0–15

PTE

Extended pause control. This field allows software to add a 16-bit additional control

parameter into the pause frame to be sent when TCTRL[TFC_PAUSE] is set. Note

that current IEEE 802.3 pause frame format requires this parameter to be set to 0.

16–31

Pause time value. Represents the 16-bit pause quanta (that is, 512 bit times). This

pause value is used as part of the pause frame to be sent when TCTRL[TFC_PAUSE]

is set. See Section 14.6.2.7, “Flow Control,” for more information.

MPC8540 Datasheet(PDF) 653 Page - Freescale Semiconductor, Inc

MPC8540 Datasheet(HTML) 653 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