HD6417660 RENESAS [Renesas Technology Corp], HD6417660 Datasheet - Page 575

• Manufacturer Part Number: HD6417660
• Description: Renesas 32-Bit RISC Microcomputer
• Manufacturer: RENESAS [Renesas Technology Corp]

19.3.20 HcRhDescriptorB Register (HRDRB)
HRDRB is the second register of two registers describing the features of the root hub. These bits
must be set during the initial setting so as to correspond to the system implementation.
Bit
31 to 18 —
17
16 to 2
1
0
Bit Name
PPCM
—
DR
—
Initial
Value
All 0
0
All 0
0
0
R/W
R
R/W
R
R/W
R
Description
Reserved
These bits are always read as 0. The write value should
always be 0. The operation is not guaranteed if 1 is
written to these bits.
Port Power Control Mask
This bit indicates whether the port is influenced by the
global power-control command when the PSM bit in the
HcRhDescriptorA register is set. When this bit is set, the
power state of the port is affected by the power control at
each port (set/clear port power). When this bit is cleared,
the port is controlled by the global power switch (set/clear
global power). If the device is placed in global switching
mode (PSM bit = 0), this bit is not valid.
Note: Clear the NPS bit in the HcRhDescriptorA register
0: Ports are controlled by the global power switch.
1: Port#1 is affected by the power control at each port.
Reserved
These bits are always read as 0. The write value should
always be 0. The operation is not guaranteed if 1 is
written to these bits.
Device Removable
This bit is dedicated to the ports of the root hub. When
this bit is cleared, the set device becomes removable.
When this bit is set, do not remove the set device.
0: Device attached to port#1 is removable.
1: Device attached to port#1 is not removable.
Reserved
This bit is always read as 0. The write value should
always be 0. The operation is not guaranteed if 1 is
written to this bit.
so that the power to all ports is off
(PortPowerStatus = 0), then set this bit.
Rev. 1.00, 02/04, page 537 of 804