USB2512B Datasheet, PDF (37/57 Pages) Microchip Technology – USB 2.0 Hi-Speed Hub Controller

USB251xB/xBi
5.5.1.2 RESET_N for EEPROM Configuration
FIGURE 5-2:
RESET_N TIMING FOR EEPROM MODE
Hardware reset
Read
Read I²C
asserted
CFG_SEL[1:0] EEPROM
Attach USB
upstream
Attach
Debounce
Interval
USB_RESET
USB_RESET State
USB Reset
Recovery
RESET_N
VSS
t1
t2
t3
t4
t6
t5
CFG_SEL[2:0]
VSS
don’t care
valid
don’t care
t7
t8
t9
t10
Name
Description
MIN
t1 RESET_N asserted
1
t2 CFG_SEL[1:0] setup time
16.7
t3 CFG_SEL[1:0] hold time
16.7
t4 Hub recovery/stabilization
t5 EEPROM read (hub configuration)
t6 USB attach (see notes)
t7 Host acknowledges attach and signals USB reset
100
t8 USB_RESET
t9 USB_RESET state
t10 USB Reset Recovery
Note 5-2
10
TYP
40
40
host-
defined
MAX
1400
500
Units
s
ns
ns
s
ms
ms
ms
ms
ms
ms
Note:
• When in bus-powered mode, the hub and its associated circuitry must not consume more than 100 mA from the
upstream USB power source during t6+t7+t8+t9.
• All power supplies must have reached the operating levels mandated in Section 6.0, "DC Parameters", prior to
(or coincident with) the assertion of RESET_N.
Note 5-2 10 ms for hubs, 50 ms for root ports.
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DS00001692C-page 37