BCM1250/BCM1125/BCM1125H
User Manual
10/21/02
B r o a d c o m C o r p o r a t i o n
Page
386
Section 12: PCMCIA Control Interface
Document
1250_1125-UM100CB-R
Software can directly control the card power using three bits in the
pcmcia_cfg
register, each bit corresponds
to one output. These signals should be connected to an external power switch that provides the card VCC.
When either CD1# or CD2# is set these bits are forced to zero and writes are ignored (i.e. software is unable
to supply power if there is no card, the pwr_ctrl bit in the
pcmcia_cfg
register can be set to keep this behaviour
when PCMCIA mode is disabled). When a card is inserted the card detect status change interrupt is used to
alert the software. The state of the VS1# and VS2# signals is then read and software sets the appropriate
configuration bits to power up the card. If the card is subsequently removed the power is automatically turned
off (as described above) and the bits in the
pcmcia_cfg
register are again cleared to zero to prevent immediate
application of power when a new card is inserted (this must be done to avoid providing the wrong voltage to
the new card).
Alternatively, VCC power management can be done entirely in hardware. This is configured by setting the
apron_en bit in the
pcmcia_cfg
register. When this bit is set, the hardware detects the VS1# and VS2# signals
and will enable the requested power to the card.
The following table summarizes the VCC power control options. This table includes the options for controlling
the power enable output bits when the PCMCIA mode is not selected at reset time (this is discussed below in
Section: “Using the Power Outputs” on page 393
).
Table 269: PCMCIA 3.3V and 5V VCC Power Enable Truth Table
Mode
Control Bits
Input signals from
PCMCIA card
Software Control
Bits in pcmcia_cfg
Card State
Power
Outputs
R
e
se
t A
D
[16]
PCM
C
IA
m
ode
ena
b
le
pcm
c
ia_
c
fg
pw
r_ctl
bit
CD1
#
GP
IO
[1
2]
CD2
#
GP
IO
[1
3]
VS1
#
GP
IO
[1
4]
VS2
#
GP
IO
[1
5]
apr
o
n
cf
g
3
v
cf
g
5
V
PC_E
N
3
V
PC_E
N
5
V
1
X
1
X
X
X
X
X
X
Not inserted
0
0
1
X
X
1
X
X
X
X
X
Not inserted
0
0
1
X
0
0
X
X
0
0
0
Inserted off
0
0
1
X
0
0
X
X
0
0
1
Inserted sw set 5V
0
1
1
X
0
0
X
X
0
1
0
Inserted sw set 3.3V
1
0
1
X
0
0
X
X
0
1
1
Inserted sw set both power matrix decodes
1
1
1
X
0
0
1
1
1
X
X
5V requested and supplied
0
1
1
X
0
0
0
1
1
X
X
3.3V requested and supplied
1
0
1
X
0
0
1
0
1
X
X
low-voltage X.XV requested none supplied
0
0
1
X
0
0
0
0
1
X
X
X.X/3.3/5V requested
3.3V supplied
1
0
0
1
1
X
X
X
X
X
X
Non-PCMCIA cd used
forced off
0
0
0
1
X
1
X
X
X
X
X
Non-PCMCIA cd used
forced off
0
0
0
1
0
0
X
X
X
0
0
Non-PCMCIA cd used
off
0
0
0
1
0
0
X
X
X
0
1
Non-PCMCIA cd used
sw set
0
1
Содержание BCM1125
Страница 18: ...BCM1250 BCM1125 BCM1125H User Manual 10 21 02 Broadcom Corporation Page xviii Document 1250_1125 UM100CB R ...
Страница 28: ...BCM1250 BCM1125 BCM1125H User Manual 10 21 02 Broadcom Corporation Page xxviii Document 1250_1125 UM100CB R ...
Страница 515: ...BCM1250 BCM1125 BCM1125H User Manual 10 21 02 Broadcom Corporation Page vii Index Document 1250_1125 UM100CB R ...