L-USS820D-DB LSI, L-USS820D-DB Datasheet - Page 45

• Manufacturer Part Number: L-USS820D-DB
• Manufacturer: LSI

Specifications of L-USS820D-DB

• Operating Temperature (min): -20C
• Operating Temperature Classification: Commercial
• Operating Temperature (max): 85C
• Rad Hardened: No
• Lead Free Status / RoHS Status: Compliant

Data Sheet, Rev. 7
September 2004
SUSPEND and RESUME Behavior
(continued)
Special SUSPEND Considerations for Bus-Powered Devices
Depending on the device design, the USS-820D register interface signals (RDN, WRN, IOCSN) could have
unknown values immediately after a SUSPEND because external components have been powered off. In this
case, firmware must configure the USS-820D to enable the locking mechanism by setting the MCSR.SUSPLOE
register bit. This mechanism protects the internal registers from being corrupted in this situation. Its behavior is
documented in Special Action Required by USS-820/USS-825 After Suspend Application Note (AP97-058CMPR-
04).
* SOFN is an output-only pin during normal operation. In certain chip test modes, this pin functions as an input.
Agere Systems Inc.
D[7:0], SOFN*: Bidirectional pins, forced to input mode while suspended (assuming SSR.SUSPPO = 1). Their
value will be determined by external logic, and must be a logic 0 or 1 to avoid current draw in the USS-820D.
IRQN, USBR, DSA: 3-statable outputs, forced to
tristate during SUSPEND (assuming SSR.SUSPPO = 1, MCSR.BDFEAT = 0). Their value will be determined by
external logic, and is a don’t care for the USS-820D.
DPLS, DMNS: Bidirectional pins, in input mode during SUSPEND, driven by USB. Since they are statically
driven to 1 and 0, respectively, there is no current draw in the USS-820D.
RWUPN: Input-only pin, driven to 1 by (powered) external logic during SUSPEND, unless/until a remote wake-up
is signalled.
SUSPN: Output-only pin, driven to 0 by USS-820D to indicate SUSPEND.
XTAL1: Input connection to internal oscillator. If a crystal is used as a clock source, there are no special consid-
erations for this pin. If an external oscillator is used as a clock source, this input must be driven to a stable 1 by
external logic.
RESET: Driven to 0 during SUSPEND by external logic.
DPPU: 3-statable output, drives a logic 1 during SUSPEND (assuming MCSR.DPEN = 1). This is required in
case the pin is used to power the external DPLS pull-up resistor, which must remain powered during SUSPEND.
(continued)
USB Device Controller
USS-820D
45