cl-ps6700 Cirrus Logic, Inc., cl-ps6700 Datasheet - Page 2

• Manufacturer Part Number: cl-ps6700
• Description: Low-power Pc Card Controller For The Cl-ps7111
• Manufacturer: Cirrus Logic, Inc.

OVERVIEW
CL-PS7111-to-CL-PS6700 Interface
The PC Card interface requires a 26-bit address bus
and a 16-bit data bus. The interface between the
CL-PS6700 and CL-PS7111 consists of a 16-bit bus
that carries the address and data information, and
several control signals. This bus defines a two-clock
address phase during which the 26-bit PC Card
address and 6 control bits are transferred, and a
one- or two-clock data phase during which one or
four bytes of data are transferred. The data phase
for reads can be deferred (for example, for a DMA
access to the frame buffer of the CL-PS7111).
If a write transfer is indicated, write data appears in
the third clock phase. If a word write is indicated,
write data also appears in the fourth clock phase.
For read transfers, the CL-PS6700 drives the bus
with read data during the first one or two clocks of
the data phase. This interface bus is also shared by
other memory devices and up to one additional
CL-PS6700 device.
The CL-PS7111 accesses the CL-PS6700 as a
memory-mapped peripheral on the 16-bit memory
bus. A Chip Enable signal (NCS[4]) from the
CL-PS7111 selects one CL-PS6700 device for
access to a particular PC Card socket. Another Chip
Enable signal (NCS[5]) connects a second PC Card
socket.
The CL-PS6700 implements the low-level interface
to the PC Card socket and provides voltage transla-
tion for mixed-voltage systems. The CL-PS6700
also provides the data buffer and interrupt controls
for the PC Card. Transfers between the two devices
can be either one or four bytes.
The CL-PS6700 can be programmed to assem-
ble/disassemble CL-PS7111 transfers to the width
of the PC Card. The CL-PS6700 has read and write
buffers that allow posting of both reads and writes.
The read queue is single entry; the write FIFO can
queue up to four CL-PS7111 transactions (up to
16 bytes).
2
OVERVIEW
(cont.)
C
I R R U S
L
O G I C
C
O N F I D E N T I A L
Hot Insertion Support
The CL-PS6700 PC Card controller allows PC
Cards to be inserted or removed while system
power is on. The CL-PS7111 controller typically
applies power to a PC Card socket after it has
detected a properly inserted card. The device
removes the power before the card is removed
(that is, when the CPU detects that the card lock is
deasserted). Since each card is isolated from the
system by the associated CL-PS6700, insertion
and removal of cards do not cause interference on
the system buses.
Card Configuration and Access
After power-on or reset, a PC Card defaults to a
memory-only card. The CL-PS7111 then reads the
CIS of the card to determine the card type, access
time, and so on, and configures the CL-PS6700 to
access the card.
Each PC Card’s V
controlled by its associated CL-PS6700. The
CL-PS7111 controls the power to a card by writing
to the CL-PS6700 registers. The CL-PS6700
ensures that its signals to the sockets are in the
proper state before applying or removing power.
The CL-PS6700 device is available in an 100-pin
VQFP package. The device can be used with both
operating frequencies of the CL-PS7111 (13 and
18 MHz at 2.7 and 3.3 V).
, N D A R
PRELIMINARY DATA BOOK v1.0
E Q U I R E D
CC
Low-Power PC Card Controller
and V
PP
pins are individually
November 1997
CL-PS6700