s1r72900 Epson Electronics America, Inc., s1r72900 Datasheet - Page 28

• Manufacturer Part Number: s1r72900
• Description: Physical Layer Ic Compliant With The Ieee 1394-1995 And Ieee 1394a-2000 Standards.
• Manufacturer: Epson Electronics America, Inc.

S1R72900F00A
7.2 Data Format
7.2.1 Self-ID packet
The Self-ID packets the SIR72900F00A transmits are 2-quadlet packets in the format shown in Figure 7.1. The
SIR72900F00A transmits the following Self-ID packet during Self-ID period of bus initialization. The SIR72900F00A
also transmits a Self-ID packet automatically as a response to a Ping packet.
phy_ID: physical_ID field
L:
gap_cnt: gap_cnt field
sp:
00 = 98.304 Mbps (S100)
01 = 98.304/196.608 Mbps (S100/S200)
10 = 98.304/196.608/393.216 Mbps (S100/S200/S300)
11 = Reserved
Applicable speeds are stored. For the SIR72900F00A, this field is fixed to '10b.'
rsv:
C:
pwr:
p0, p1: Port connection status field
24
0
#
1 2 3 4
Reflects the ID node of the IC.
LPS, LCtrl field
Reflects the logical multiplication of the LPS pin and the LCtrl bit of PHY Register 4 at the time of Self-ID
packet transmission.
Reflects the value of Gap_Count of PHY Register 1.
PHY_SPEED field
Fixed to '00b.'
CONTENDER field
Reflects the value of the Contender bit of PHY Register 4.
POWER_CLASS field
Reflects the Pwr bit of PHY Register 4.
The IEEE P1394a-2000 standards define this field as follows:
Indicates the port status.
bit21 = PS0(Pin22)
bit22 = PS1(Pin21)
bit23 = PS2(Pin20)
000 = The node does not need a power supply. The node does not repeat the power supply.
001 = The node has its own power supply and is able to supply a minimum of 15 W.
010 = The node has its own power supply and is able to supply a minimum of 30 W.
011 = The node has its own power supply and is able to supply a minimum of 45 W.
100 = The node can consume power up to 3 W from the cable. However, it does not consume any power
101 = Reserved
110 = The node can consume power up to 3 W from the cable. It can consume more power up to 3 W to
111 = The node can consume power up to 3 W from the cable. It can consume more power up to 7 W to
11 = The port is active and connected to a child node.
10 = The port is active and connected to a parent node.
01 = The port is inactive (disabled, disconnected, or suspended).
phy-ID
to enable the Link or upper layers.
enable the Link or upper layers.
enable the Link or upper layers.
5 6 7 8 9
0 L
# # # # # # # # # # # # # # # # # # # # # #
Figure 7.1 Self-ID packet format
gap_cnt
logical inverse of first quadlet
EPSON
sp
rsv
c
pwr
p0
p1
0
Rev. 1.0
i m