
June 1997
15
ADVANCE DATA BOOK v2.0
PIN DESCRIPTIONS
CL-PS7500FE
System-on-a-Chip for Internet Appliance
2.
PIN DESCRIPTIONS
This chapter gives the name, type, and relevant details of each of the CL-PS7500FE signals.
NOTE:
When output signals are placed in the high-impedance state for long periods, ensure that they do not ‘float’
to an undefined logic level.
The following abbreiviations are used to indicate signal types.
For outputs and bidirectional signals, drive strength is classified 1, 2, or 3. See
Chapter 22
for DC and AC
characteristics.
IC
Input, CMOS threshold
OCZ
Output, CMOS levels, tristate
IT
ICS
IA
OA
BTZ
TOD
CSOD
IAOD
Input, TTL threshold
Input, CMOS Schmitt
Input, analog
Output, analog
Bidirectional, CMOS output, TTL threshold input level
Open-drain, TTL input
Open-drain, CMOS schmitt input
Input, analog with programmable internal pull-down transistor
2.1
CL-PS7500FE Pin Descriptions
Name
Type
Drive
Strength
Description
LA[28:0]
OCZ
2
LATCHED ADDRESS BUS:
This bus is the latched version of the
ARM address for memory accesses, changing on the falling edge of
the internal MCLK signal.
LNBW
OCZ
2
LATCHED NOT BYTE WORD:
This is a latched version of the inter-
nal NBW signal from the ARM processor, changing on the falling
edge of the internal MCLK signal.
D[31:0]
BTZ
2
DATA:
The main data bus for the CL-PS7500FE. All external data
transfers happen through this bus. When the CL-PS7500FE is con-
figured for operation in 16-bit mode, only the lower 16 bits are used.
SnA
IC
SYNCHRONOUS/NOT ASYNCHRONOUS
: This pin is set accord-
ing to the relationship required between the internal clock signals,
MCLK and FCLK, for the ARM.
If this pin is set high, both the memory system and the CPU are
driven from the MEMCLK pin, and the required synchronous timing
relationship between the ARM processor clocks is generated auto-
matically on-chip. If different clocks are to be used for the MEMCLK
and CPUCLK inputs, the SnA pin must be set low.