2-Port USB 2.0 Hi-Speed Hub Controller
Datasheet
2014 Microchip Technology Inc.
DS00001726A-page 13
17
SUSP_IND
I/O12
Suspend Indicator:
Indicates the USB state of the hub.
negated : unconfigured, or configured and in USB Suspend
asserted : Hub is configured, and is active (i.e., not in suspend)
LOCAL_PWR
Local Power:
This input selects whether the hub reports itself as bus or self-powered
when dynamic power switching is enabled via the
Configuration Data Byte 2 Register
. This pin is sampled at POR/Reset before the USB Hub Attach
command is sent. Once the hub has entered the attach state (as
indicated by the
USB Attach and Write Protect (USB_ATTACH)
bit of
the
Status/Command Register (STCD)
), this pin cannot be changed.
Low : self/local power source is not available (i.e., the Hub gets all
power from the upstream USB VBus).
High : self/local power source is available.
Note:
Never tie this pin directly to
VDD33
, as doing so may cause
it to act as
SUSP_IND
.
Note:
This pin assumes the meaning of local power input only if
properly configured via SMBus. If the hub is configured via
straps, it is NON_REM0 at reset and SUSP_IND after reset.
(NON_REM0)
Non-Removable Port Strap Option:
This pin is sampled (in conjunction with
SUSP_IND/NON_REM0
) at
RESET_N
negation to determine if ports [2:1] contain permanently
attached (non-removable) devices:
NON_REM[1:0] =
00
: all ports are removable
NON_REM[1:0] =
01
: port 1 is non-removable
NON_REM[1:0] =
10
: ports 1 and 2 are non-removable
NON_REM[1:0] =
11
: reserved
See
Section 2.5, "Strap Pin Configuration"
for details.
POWER, GROUND, and NO CONNECTS
1
9
18
VDD33
3.3 V power to the chip.
A 1.0
μ
F low-ESR capacitor to VSS is required on pin 9 as close as
possible to the pin. A 0.1
μ
F low-ESR capacitor to VSS is required on
pin 1 as close as possible to the pin.
10
CRFILT
VDD Core Regulator Filter Capacitor:
This pin requires a 1.0
μ
F low-ESR capacitor to VSS for proper
operation.
23
PLLFILT
PLL Regulator Filter Capacitor:
This pin can have up to a 0.1
μ
F low-ESR capacitor to VSS, or be left
unconnected.
VSS
Ground Pad/ePad:
The package slug is the only VSS for the device and must be tied to
ground with multiple vias.
Table 2.2 USB2422 Pin Descriptions (continued)
PIN
#
SYMBOL
BUFFER
TYPE
DESCRIPTION
