PI7C8150BNDIE Pericom Semiconductor, PI7C8150BNDIE Datasheet - Page 70

• Manufacturer Part Number: PI7C8150BNDIE
• Description: IC PCI-PCI BRIDGE ASYNC 256-PBGA
• Manufacturer: Pericom Semiconductor

Specifications of PI7C8150BNDIE

• Applications: *
• Interface: *
• Voltage - Supply: *
• Package / Case: 256-PBGA
• Mounting Type: Surface Mount
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

10.3
Table 10-2. GPIO Serial Data Format
The first 8 bits contain the PRSNT#[1:0] signal values for four slots, and these bits control
the S_CLKOUT[3:0] outputs. If one or both of the PRSNT#[1:0] signals are 0, that
indicates that a card is present in the slot and therefore the secondary clock for that slot is
not masked. If these clocks are connected to devices and not to slots, one or both of the bits
should be tied low to enable the clock.
The next 5 bits are the clock mask for devices; each bit enables or disables the clock for
one device. These bits control the S_CLKOUT[8:4] outputs: 0 enables the clock, and 1
disables the clock.
Bit 13 is the clock enable bit for S_CLKOUT[9], which is connected to PI7C8150B’s
S_CLKIN input.
If desired, the assignment of S_CLKOUT outputs to slots, devices, and PI7C8150B’s
S_CLKIN input can be rearranged from the assignment shown here. However, it is
important that the serial data stream format match the assignment of S_CLKOUT.
The 8 least significant bits are connected to the PRSNT# pins for the slots. The next 5 bits
are tied high to disable their respective secondary clocks because those clocks are not
connected to anything. The next bit is tied LOW because that secondary clock output is
connected to the PI7C8150B S_CLKIN input. When the secondary reset signal, S_RST_L,
is detected asserted and the primary reset signal, P_RST_L, is detected deasserted,
PI7C8150B drives GPIO[2] LOW for one cycle to load the clock mask inputs into the shift
register. On the next cycle, PI7C8150B drives GPIO[2] HIGH to perform a shift operation.
This shifts the clock mask into MSK_IN; the most significant bit is shifted in first, and the
least significant bit is shifted in last.
After the shift operation is complete, PI7C8150B tri-states the GPIO signals and can
deassert S_RST_L if the secondary reset bit is clear. PI7C8150B then ignores MSK_IN.
Control of the GPIO signal now reverts to PI7C8150B GPIO control registers. The clock
disable mask can be modified subsequently through a configuration write command to the
secondary clock control register in device-specific configuration space.
LIVE INSERTION
The GPIO[3] pin can be used, along with a live insertion mode bit, to disable transaction
forwarding.
[1:0]
[3:2]
[5:4]
[7:6]
[8]
[9]
[10]
[11]
[12]
[13]
[14]
[15]
Bit
Slot 0 PRSNT#[1:0] or device 0
Slot 1 PRSNT#[1:0] or device 1
Slot 2 PRSNT#[1:0] or device 2
Slot 3 PRSNT#[1:0] or device 3
Device 4
Device 5
Device 6
Device 7
Device 8
PI7C8150B S_CLKIN
Reserved
Reserved
Page 70 of 109
ASYNCHRONOUS 2-PORT PCI-TO-PCI BRIDGE
Description
ADVANCE INFORMATION
April 2009 – Revision 1.08
0
1
2
3
4
5
6
7
8
9
NA
NA
S_CLKOUT
PI7C8150B