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
384
Section 12: PCMCIA Control Interface
Document
1250_1125-UM100CB-R
D
IRECT
C
ONNECTION
OF
A
M
EMORY
O
NLY
C
ARD
shows the connections between the interface and the memory only PCMCIA slot. Chip select region
6 of the generic bus is configured in multiplexed mode and set for a 16 bit wide device. To allow hot-swap the
card signals must be isolated from the generic bus. For the 26 address bits the buffering can be done by the
address latch. For the data, a bidirectional buffer is needed.
The databus connections for the PCMCIA card reflect the little endian nature of the PCMCIA bus and the big
endian byte lane assignment on the generic bus. So data[7:0] of the PCMCIA slot should connect via an
isolation buffer to IO_AD[31:24] and data[15:8] of the PCMCIA slot should connect through a buffer to
IO_AD[23:16]. This allows use of both 8 bit and 16 bit cards.
Figure 80: Example PCMCIA Slot Connection
PCMCIA card slot
SB-1250
26
oe
lat
373
16245
IO_ALE
IO_AD
IO_CS_L[6]
IO_OE_L
IO_WR_L
16
A[25:0]
D[15:8]
OE#
WE#
REG#
WP
CD1#
CD2#
VS1#
VS2#
READY
RESET
Vcc1
Vcc2
Vpp1
Vpp2
PCMCIA power
switch
(eg MAX1602)
PC_WP
PC_CD1_L
PC_CD2_L2
PC_VS1_L
PC_VS2_L
PC_READY
PC_RESET
PC_EN5V
PC_EN3V
PC_ENVPP
PC_REG_L
CE1#
PC_CE1_L
CE2#
PC_CE2_L
3.3V
3.3V
3.3V
3.3V
[31:16]
D[7:0]
[23:16]
[31:24]