Table 3−4. TPS2226 Control Logic—xVPP
AVPP CONTROL SIGNALS
OUTPUT
V_AVPP
BVPP CONTROL SIGNALS
OUTPUT
V_BVPP
D8(SHDN)
D0
0
D1
0
D9
X
0
D8(SHDN)
D4
0
D5
0
D10
X
1
1
1
1
1
0
0 V
3.3 V
5 V
1
1
1
1
1
0
0 V
3.3 V
5 V
0
1
0
1
0
0
1
1
0
1
1
1
0
X
X
X
12 V
Hi-Z
Hi-Z
1
0
X
12 V
Hi-Z
Hi-Z
1
1
1
1
X
X
X
X
X
X
Table 3−5. TPS2226 Control Logic—xVCC
AVCC CONTROL SIGNALS
OUTPUT
V_AVCC
BVCC CONTROL SIGNALS
OUTPUT
V_BVCC
D8(SHDN)
D3
0
D2
0
D8(SHDN)
D6
0
D7
0
1
1
1
1
0
0 V
3.3 V
5 V
1
1
1
1
0
0 V
3.3 V
5 V
0
1
0
1
1
0
1
0
1
1
0 V
1
1
0 V
X
X
Hi-Z
X
X
Hi-Z
3.5.6 Internal Ring Oscillator
The internal ring oscillator provides an internal clock source for the PCI6x21/PCI6x11 controller so that neither the
PCI clock nor an external clock is required in order for the PCI6x21/PCI6x11 controller to power down a socket or
interrogate a PC Card. This internal oscillator, operating nominally at 16 kHz, is always enabled.
3.5.7 Integrated Pullup Resistors for PC Card Interface
The PC Card Standard requires pullup resistors on various terminals to support both CardBus and 16-bit PC Card
configurations. The PCI6x21/PCI6x11 controller has integrated all of these pullup resistors and requires no additional
external components. The I/O buffer on the BVD1(STSCHG)/CSTSCHG terminal has the capability to switch to an
internal pullup resistor when a 16-bit PC Card is inserted, or switch to an internal pulldown resistor when a CardBus
card is inserted. This prevents inadvertent CSTSCHG events. The pullup resistor requirements for the various
UltraMedia interfaces are either included in the UltraMedia cards (or the UltraMedia adapter) or are part of the existing
PCMCIA architecture. The PCI6x21/PCI6x11 controller does not require any additional components for UltraMedia
support.
3.5.8 SPKROUT and CAUDPWM Usage
The SPKROUT terminal carries the digital audio signal from the PC Card to the system. When a 16-bit PC Card is
configured for I/O mode, the BVD2 terminal becomes the SPKR input terminal from the card. This terminal, in
CardBus applications, is referred to as CAUDIO. SPKR passes a TTL-level binary audio signal to the
PCI6x21/PCI6x11 controller. The CardBus CAUDIO signal also can pass a single-amplitude binary waveform as well
as a PWM signal. The binary audio signal from each PC Card sockets is enabled by bit 1 (SPKROUTEN) of the card
control register (PCI offset 91h, see Section 4.38).
Older controllers support CAUDIO in binary or PWM mode, but use the same output terminal (SPKROUT). Some
audio chips may not support both modes on one terminal and may have a separate terminal for binary and PWM.
The PCI6x21/PCI6x11 implementation includes a signal for PWM, CAUDPWM, which can be routed to an MFUNC
terminal. Bit 2 (AUD2MUX), located in the card control register, is programmed to route a CardBus CAUDIO PWM
terminal to CAUDPWM. See Section 4.36, Multifunction Routing Register, for details on configuring the MFUNC
terminals.
Figure 3−4 illustrates the SPKROUT connection.
3−7
TI [ TEXAS INSTRUMENTS ]
