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MV78100 Datasheet, PDF (51/124 Pages) – | |||
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7.2
System Power Up and Reset Settings
Hardware Reset
Hardware Reset
The MV78100 has one reset input pin â SYSRSTn. When asserted, the entire chip is placed in its
initial state. All outputs are placed in high-z.
The following output pins are still active during SYSRSTn assertion:
 TCLK_OUT
 GE0_TXCLKOUT
 M_CLKOUT[2:0], M_CLKOUTn[2:0]
 M_CKE[3:0]
 M_ODT[3:0]
 M_STARTBURST
 SATAx_TX_P
 SATAx_TX_N
 PEXx_TX_N
 PEXx_TX_P
 USBx_DM
 USBx_DP
The MV78100 has an optional SYSRST_OUTn open drain output signal, multiplexed on MPP pins,
that is used as a reset request from the MV78100 to the board reset logic. This signal is set when
one of the following maskable events occurs:
 Received hot reset indication from the PCI Express port 0.0 link (only relevant when used as a
PCI Express endpoint), and bit <PexRstOutEn> is set to 1 in the RSTOUTn Mask Register (see
the Reset register section of the MV78100 User Manual). In this case, SYSRST_OUTn is
asserted for duration of ~300 TCLK cycles.
 PCI Express port 0.0 link failure (only relevant when used as a PCI Express endpoint), and bit
<PexRstOutEn> is set to 1 in the RSTOUTn Mask Register (see the Reset register section of
the MV78100 User Manual). In this case, SYSRST_OUTn is asserted for duration of ~300
TCLK cycles .
 Watchdog timer expiration and bit <WDRstOutEn> is set to 1 in the RSTOUTn Mask Register
(see the Reset register section of the MV78100 User Manual).
 Bit <SystemSoftRst> is set to 1 in System Soft Reset Register and bit <SoftRstOutEn> is set to
1 in RSTOUTn Mask Register.
7.3
Note
Reset must be active for a minimum length of 100ms. Core power, I/O power, and
analog power must be stable (VDD +/- 5%) during that time and onward.
PCI Express Reset
As a Root Complex, the MV78100 can generate a Hot Reset to the PCI Express port. Upon CPU
setting the PCI Express Control registerâs <conf_mstr_hot_reset> bit, the PCI Express unit sends a
Hot Reset indication to the Endpoint (see the PCI Express Interface section in the MV76100,
MV78100, and MV78200 Functional Specification).
When the MV78100 works as an Endpoint, and a Hot Reset packet is received:
 A maskable interrupt is asserted
 If the PCI Express Debug Control registerâs <conf_dis_hot_rst_reg_rst> is cleared, the
MV78100 also resets the PCI Express register file to its default values.
 The MV78100 triggers an internal reset, if not masked by PCI Express Debug Control registerâs
<conf_msk_hot_reset> bit.
Copyright © 2008 Marvell
December 6, 2008, Preliminary
Document Classification: Proprietary Information
MV-S104552-U0 Rev. D
Page 51
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