
1: INTERFACING TO THE PC CARD BUS
5-6
EPSON
S1D13806 SERIES
APPLICATION NOTES (X28B-G-005-01)
1.3.2 PC Card Host Bus Interface Signals
The S1D13806 PC Card Host Bus Interface is designed to support processors which interface the
S1D13806 through the PC Card bus.
The S1D13806 PC Card Host Bus Interface requires the following signals from the PC Card bus.
BUSCLK is a clock input which is required by the S1D13806 Host Bus Interface. It is separate
from the input clock (CLKI) and is typically driven by the host CPU system clock. Since PC Card
signalling is independent of any clock, BUSCLK can come from any oscillator already imple-
mented. For example, the source for the CLKI input of the S1D13806 may be used.
The address inputs AB[20:0], and the data bus DB[15:0], connect directly to the PC Card address
(A[20:0]) and data bus (D[15:0]), respectively. CONF[3:0] must be set to select the PC Card Host
Bus Interface with little endian mode.
M/R# (memory/register) selects between memory or register access. It may be connected to an
address line, allowing system address A21 to control M/R#.
Chip Select (CS#) must be driven low whenever the S1D13806 is accessed by the PC Card bus.
WE1# and RD/WR# connect to -CE2 and -CE1 (the byte enables for the high-order and low-order
bytes). They are driven low when the PC Card bus is accessing the S1D13806.
RD# connects to -OE (the read enable signal from the PC Card bus).
WE0# connects to -WE (the write enable signal from the PC Card bus).
WAIT# is a signal output from the S1D13806 that indicates the PC Card bus must wait until data
is ready (read cycle) or accepted (write cycle) on the host bus. Since PC Card bus accesses to the
S1D13806 may occur asynchronously to the display update, it is possible that contention may
occur in accessing the S1D13806 internal registers and/or display buffer. The WAIT# line
resolves these contentions by forcing the host to wait until the resource arbitration is complete.
The Bus Start (BS#) signal is not used for the PC Card Host Bus Interface and should be tied high
(connected to VDD).
The RESET# (active low) input of the S1D13806 may be connected to the PC Card RESET
(active high) using an inverter.