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Interfacing to the Toshiba MIPS TX3912 Processor S1D13505
Issue Date: 01/02/05 X23A-G-010-04
4 Direct Connection to the Toshiba TX3912
The S1D13505 was specifically designed to support the Toshiba MIPS TX3912 processor.
When configured, the S1D13505 will utilize one of the PC Card slots supported by the
processor.
4.1 Hardware Description
In this example implementation, the S1D13505 occupies one PC Card slot and resides in
the Attribute and IO address range. The processor provides address bits A[12:0], with
A[23:13] being multiplexed and available on the falling edge of ALE. Peripherals r equiring
more than 8K bytes of address space would require an external latch for thes e multi ple xed
bits. However, the S1D13505 has an internal latch specifically designed for this processor
making additional logic unnecessary. To further reduce the need f or external components,
the S1D13505 has an optional BUSCLK divide-by-2 feature, allowing the high speed
DCLKOUT from the processor to be directly connected to the BUSCLK input of the
S1D13505. An optional external oscillator may be used for BUSCLK since the S1D13505
will accept host bus control signals asynchronously with respect to BUSCLK.
The following diagram shows a typical im plementation of the interface.
Figure 4-1: Typical Implementation of Direct Connection
TX3912
WE*
D[31:24]
CARDxCSL*
RD*
CARDxWAIT*
A[12:0]
DCLKOUT
WE0#
RD/WR#
AB[12:0]
DB[7:0]
WE1#
BS#
RD#
M/R#
CS#
BUSCLK
WAIT#
RESET#
CARDxCSH*
AB[16:13]
ALE
CARDREG*
CARDIORD*
AB20
AB19
AB18
AB17
CARDIOWR*
S1D13505
D[23:16] DB[15:8]
ENDIAN
VDD (+3.3V)
System RESET
pull-up
VDD
Oscillator
...or...
CLKI
See text
When connecting the S1D13505 RESET# pin, the system designer should be aware of all
conditions that may reset the S1D13505 (e.g. CPU reset can be asserted during wake-up
from power-down modes, or during debug states).
Note: