ISP1160
Embedded USB Host Controller
Philips Semiconductors
Table 29: HcRhDescriptorA register: bit description…continued
Bit
Symbol
Description
9
NPS
NoPowerSwitching: This bit is used to specify whether power
switching is supported or ports are always powered. When this bit
is cleared, bit PowerSwitchingMode specifies global or per-port
switching.
0 — ports are power switched
1 — ports are always powered on when the HC is powered on
8
PSM
PowerSwitchingMode: This bit is used to specify how the power
switching of the Root Hub ports is controlled. This field is valid only
if the NoPowerSwitching field is cleared.
0 — all ports are powered at the same time
1 — each port is powered individually. This mode allows port
power to be controlled by either the global switch or per-port
switching. If bit PortPowerControlMask is set, the port responds to
only port power commands (Set/ClearPortPower). If the port mask
is cleared, then the port is controlled only by the global power
switch (Set/ClearGlobalPower).
7 to 2
1 to 0
-
reserved
NDP[1:0]
NumberDownstreamPorts: These bits specify the number of
downstream ports supported by the Root Hub. The maximum
number of ports supported by the ISP1160 is 2.
10.3.2 HcRhDescriptorB register (R/W: 13H/93H)
The HcRhDescriptorB register is the second register of two describing the
characteristics of the Root Hub. These fields are written during initialization to
correspond with the system implementation. Reset values are
implementation-specific (IS).
Code (Hex): 13 — read
Code (Hex): 93 — write
Table 30: HcRhDescriptorB register: bit allocation
Bit
31
30
29
28
27
26
25
24
Symbol
Reset
Access
Bit
reserved
N/A
R
N/A
R
N/A
R
N/A
R
N/A
R
N/A
R
N/A
N/A
R
R
23
22
21
20
19
18
17
16
Symbol
Reset
Access
Bit
reserved
N/A
R
PPCM[2:0]
N/A
R
N/A
R
N/A
R
N/A
R
IS
R/W
10
IS
R/W
9
IS
R/W
8
15
14
13
12
11
Symbol
Reset
Access
reserved
N/A
R
N/A
R
N/A
R
N/A
R
N/A
R
N/A
R
N/A
R
N/A
R
9397 750 11371
© Koninklijke Philips Electronics N.V. 2003. All rights reserved.
Product data
Rev. 04 — 04 July 2003
50 of 88
NXP [ NXP ]
