SMSC USB2502 5.6.1.3RESET_N for SMBus Slave Configuration

2-Port USB 2.0 Hub Controller

Datasheet

„All Power Supplies must have reached the operating levels mandated in Section Chapter 7, "DC Parameters", prior to (or coincident with) the assertion of RESET_N.

5.6.1.3RESET_N for SMBus Slave Configuration

Hardware				Attach			Start
	Reset	SMBus Code	Hub PHY		USB Reset		completion
reset				USB		Idle
	Negation	Load	Stabilization		recovery		request
asserted				Upstream
							response

t1 t2 t3 t4 t5 t6 t7

RESET_N

VSS

Figure 5.4 Reset_N Timing for SMBus Mode

Table 5.7 Reset_N Timing for SMBus Mode

NAME	DESCRIPTION	MIN	TYP	MAX	UNITS
t1	RESET_N Asserted.	1			μsec
t2	Hub Recovery/Stabilization.			500	μsec
t3	SMBus Code Load (See Note).		10	99.5	msec
t4	Hub Configuration and USB Attach.			100	msec
t5	Host acknowledges attach and signals USB	100			msec
	Reset.
t6	USB Idle.		Undefined		msec
t7	Completion time for requests (with or without data			5	msec
	stage).

Notes:

„For Bus-Powered configurations, the 99.5ms (MAX) is required, and the Hub and its associated circuitry must not consume more than 100mA from the upstream USB power source during t2+t3+t4+t5+t6+t7. For Self-Powered configurations, t3 MAX is not applicable and the time to load the configuration is determined by the external SMBus host.

„All Power Supplies must have reached the operating levels mandated in Section Chapter 7, "DC Parameters", prior to (or coincident with) the assertion of RESET_N.

SMSC USB2502	35	Revision 2.3 (08-27-07)
	DATASHEET