MSM60808 datasheet(13/92 Pages) OKI

13 / 92 page

¡ Semiconductor

MSM60808

1.9 Socket Power Control

The MSM60808 has functions to control power. It performs socket power control through its internal

SocketPresentRegister(PRESENT),SocketControlRegister(CONTROL),CCD#[2:1],andCVS[2:1].

Power-up of both 16-bit cards and CardBus cards is done after card detection by software reading

the PRESENT register and writing the contents to the CONTROL register. The MSM60808 uses the

contents to output signals directly to the TI TPS2202AI, a socket power control IC.

The TI TPS2202AI has three control lines (clock, data, latch) with which MSM60808 performs serial

data transfers. Transfer speed is the clock from dividing the PCI bus clock by 16. Figure 1.5 and Table

1.5 show the serial data transfer protocol and contents. For details on the TI TPS2202AI, please refer

to the TI TPS2202AI data sheet.

When PCIRST# is generated, register power is reset, prompting power-down. Power-down is

performed automatically, without software writes to registers. For card removal power-down, data

will be transferred only to the socket from which the card was removed. However, when reset by

PCIRST#, the D8 bit (shutdown bit) will output low and both sockets will power down (at other times

the D8 bit will always output high).

Clock

Data

Latch

Figure 1.5 Control Output Signals For Power Control IC

Table 1.5 Control Output Signals For Power Control IC

Socket B

Socket A

SHDN

VCC

VPP

VCC

Hi-Z

12V

3.3V

VCC

3.3V

VCC

0V0

00V0

XXXXX

XXXXXX

MSM60808 Datasheet(PDF) 13 Page - OKI electronic componets