Broadcom NetXtreme/NetLink BCM5718 Series User Manual

Central Power Management Unit (CPMU) RegistersBCM5718 Programmer’s Guide
Broadcom®
January 29, 2016 • 5718-PG108-R Page 406
Miscellaneous Control Register (offset: 0x36AC)
Name Bits Access
Default
Value
Description
Reserved 31:26 DC 0x0 –
Speculative early L1 exit mode 25:24 RW 0x0 Mode control for speculative early L1 exit.
2'b00: Enable speculative early L1 exit when
Ethernet is linked to 1000 Mb/s only
2'b01: Enable speculative early L1 exit
regardless link speed
2'b10: Disabled speculative early L1 exit
2'b11: Reserved
Speculative early L1 exit delay 23:16 RW 0x0 Delay control for speculative early L1 exit
detection. The detection circuit uses the earliest
receive packet indicator after mac address
filtering circuit. Each increment increases the
delay by 10.240 µS.
0x0: no delay
0x1: 10.24 µs delay
0x2: 20.48 µs delay
..
..
0xFF: 2621.44 µs delay
The optimal value of this delay is a function of link
speed, packet size, L1 exit latency, L1 entrance
inactive timer value and the following simulation
data.
1000 MB/s 1518byte packet–advances l1aspm
exiting by 13.880 µs with no delay
1000 MB/s 64byte packet–advances l1aspm
exiting by 2.488 µs with no delay
100 MB/s 1518byte packet–advances l1aspm
exiting by 129.377 µs with no delay
100 MB/s 64byte packet–advances l1aspm
exiting by 13.217 µs with no delay
10 MB/s 1518byte packet–advances l1aspm
exiting by 1274.94 µs with no delay
10 MB/s 64byte packet–advances l1aspm
exiting by 113.98 µs with no delay
Reserved 15:0 DC 0x0 –

Broadcom NetXtreme/NetLink BCM5718 Series Specifications

General

Brand	Broadcom
Model	NetXtreme/NetLink BCM5718 Series
Category	Controller
Language	English