Datasheet

TUSB1310A
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SLLSE32E NOVEMBER 2010REVISED JULY 2012
3.3.1 USB Power Management
The USB 3.0 specification improves power consumption by defining 4 power states, U0, U1, U2, and U3
while the PIPE specification defines P0, P1, P2 and P3. The POWER_DOWN pin states are mapped to
LTSSM states as described in Table 3-2. For all power state transitions, the Link Layer Controller must not
begin any operational sequences or further power state transitions until the TUSB1310A has indicated that
the internal state transition is completed.
Table 3-2. Power States
PIPE
POWER USB POWER STATE PCLK PLL TRANSMITTING RECEIVING PHY_STATUS
STATE
U0, all other LTSSM
P0 On On Active or Idle or LFPS Active or Idle A single cycle assertion
states
P1 U1 On On Idle or LFPS Idle A single cycle assertion
U2, RxDetect, Idle or LFPS or
P2 On On Idle A single cycle assertion
SS.Inactive RxDetect
PHY_STATUS is
Off. The PIPE is in asserted before PCLK is
P3 U3, SS.disabled an asynchronous Off LFPS or RxDetect Idle turned off and de-
mode asserted when PCLK is
fully off.
When the Link Layer Controller wants to transmit LFPS in P1, P2, or P3 state, it must de-assert
TX_ELECIDLE. The TUSB1310A generates valid LFPS until the TX_ELECIDLE is asserted. The Link
Layer Controller must assert TX_ELECIDLE before transitioning to P0.
When RX_ELECIDLE is de-asserted in P0, P1, P2, or P3, the TUSB1310A receiver monitors for LFPS
except during reset or when RX_TERMINATION is removed for electrical idle.
When the TUSB1310A is in P0 and is actively transmitting; only RX_POLARITY can be asserted.
Table 3-3. PIPE Control Pin Matrix
POWER STATE TX_DETRX_LPBK TX_ELECIDLE DESCRIPTION
0 0 Transmitting data on TX_DATA.
0 1 Not transmitting and is in electrical idle
P0
1 0 Goes into loopback mode
1 1 Transmits LFPS signaling
0 Transmits LFPS signaling
P1 Don’t care
1 Not transmitting and is in electrical idle
Don’t care 0 Transmits LFPS signaling
P2 0 1 Idle
1 1 Does a receiver detection operation
0 Transmits LFPS signaling
P3 Don’t care
1 Does a receiver detection operation
Copyright © 2010–2012, Texas Instruments Incorporated FUNCTIONAL DESCRIPTION 19
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