PNX1501E NXP Semiconductors, PNX1501E Datasheet - Page 718

• Manufacturer Part Number: PNX1501E
• Description: Digital Signal Processors & Controllers (DSP, DSC) MEDIA PROCESSOR PNX15XX/266MHZ
• Manufacturer: NXP Semiconductors

Specifications of PNX1501E

• Product: DSPs
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• Package / Case: SOT-795
• Minimum Operating Temperature: 0 C
• Lead Free Status / Rohs Status: Details
• Other names: PNX1501E,557

Philips Semiconductors
Volume 1 of 1
12NC 9397 750 14321
Product data sheet
Figure 10: Real-time/non-real-time transmit example
TxRt descriptors
Tx descriptors
Block zone
Tx clk cycles 0
LAN
Expired
P1
P2
P3
50
PRT1@90,
Real-time/non-real-time example
Figure 10
Prt2@110,
In this example initially both transmission queues have three descriptors; the first
packet in the real-time queue must be transmitted at time-stamp 90, the second
packet must be transmitted at time-stamp 110, and the third packet must be
transmitted at time-stamp 260. The packets in the non-real-time queue will be
transmitted as soon as possible.
In this example the BlockZone register is set to 30 time-stamp cycles.
After the device driver has set up the descriptors at time-stamp 50, the LAN100 starts
transmission. The initial real-time packet need not be transmitted yet, so a packet
from the non-real-time queue is transmitted first. During transmission of the
non-real-time packet, the time-stamp of the first real-time packet expires, and the
real-time packet will be transmitted as soon as transmission of the non-real-time
packet completes.
After transmitting the first real-time packet, the time-stamp of the second real-time
packet expires, and the transmission of the second real-time packet commences as
soon as the first real-time packet completes transmission.
After sending the second real-time packet, no new packets are sent out, since the
time-stamp is within the range of the block zone of the third real-time packet. As soon
as the Time-stamp Counter passes the packet’s time-stamp, the third real-time packet
is transmitted.
After completing transmission of the third real-time packet, the real-time queue is
empty, and the remaining non-real-time packets are transmitted as soon as possible.
Prt3@260
P1
100
shows an example of real-time and non-real-time traffic.
Prt1
150
Rev. 2 — 1 December 2004
PRT2@110,
Prt3@260
Prt2
Chapter 23: LAN100 — Ethernet Media Access Controller
200
250
P2
P3
Prt3@260
300
Prt3
© Koninklijke Philips Electronics N.V. 2002-2003-2004. All rights reserved.
350
P2
PNX15xx Series
400
P3
P3
450
500
23-56