USB7252PT-ISLASHKDX datasheet(44/64 Pages) MICROCHIP

44 / 64 page

USB7252P

DS00003561A-page 44



2018 - 2020 Microchip Technology Inc.

For detailed information on utilizing the USB to UART bridging feature, refer to the application note “USB to UART Bridg-

ing with Microchip USB7202 and USB725x Hubs”, which can be found on the Microchip USB7252P product page at

www.microchip.com/USB7252P.

8.12 Link Power Management (LPM)

The device supports the L0 (On), L1 (Sleep), and L2 (Suspend) link power management states. These supported LPM

states offer low transitional latencies in the tens of microseconds versus the much longer latencies of the traditional USB

suspend/resume in the tens of milliseconds. The supported LPM states are detailed in Table 8-1.

8.13 Resets

The device includes the following chip-level reset sources:

• Power-On Reset (POR)

• External Chip Reset (RESET_N)

• USB Bus Reset

8.13.1

POWER-ON RESET (POR)

A power-on reset occurs whenever power is initially supplied to the device, or if power is removed and reapplied to the

device. A timer within the device will assert the internal reset per the specifications listed in Section 9.6.2, Power-On

and Configuration Strap Timing.

8.13.2

EXTERNAL CHIP RESET (

RESET_N)

A valid hardware reset is defined as assertion of

RESET_N, after all power supplies are within operating range, per the

specifications in Section 9.6.3, Reset and Configuration Strap Timing. While reset is asserted, the device (and its asso-

ciated external circuitry) enters Standby Mode and consumes minimal current.

Assertion of

RESET_N causes the following:

1. The PHY is disabled and the differential pairs will be in a high-impedance state.

2. All transactions immediately terminate; no states are saved.

3. All internal registers return to the default state.

4. The external crystal oscillator is halted.

5. The PLL is halted.

TABLE 8-1:

LPM STATE DEFINITIONS

State

Description

Entry/Exit Time to L0

Suspend

Entry: ~3 ms

Exit: ~2 ms (from start of RESUME)

Sleep

Entry: <10 us

Exit: <50 us

Fully Enabled (On)

Note:

All power supplies must have reached the operating levels mandated in Section 9.2, Operating Condi-

tions**, prior to (or coincident with) the assertion of

RESET_N.

USB7252PT-I/KDX 데이터시트(PDF) 44 Page - Microchip Technology

USB7252PT-I/KDX 데이터시트(HTML) 44 Page - Microchip Technology

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64

데이터시트 다운로드

링크 URL