SAF-C164SM Infineon Technologies, SAF-C164SM Datasheet - Page 47

• Manufacturer Part Number: SAF-C164SM
• Description: 16-Bit CMOS Microcontroller
• Manufacturer: Infineon Technologies

3.3
The C164CM is capable of using an address space of up to 16 MBytes. Only parts of this
address space are occupied by internal memory areas. All addresses which are not used
for on-chip memory (ROM/Flash/OTP or RAM) or for registers may reference external
memory locations. This external memory is accessed via the C164CM’s external bus
interface.
The C164CM supports four different bus types:
• Multiplexed 16-bit Bus
• Multiplexed 8-bit Bus
• Demultiplexed 16-bit Bus with address on PORT1 and data on PORT0
• Demultiplexed 8-bit Bus
Due to the low pin-count of the C164CM the external memory which can be directly
addressed via the address bus is quite limited. However, the majority of applications is
expected to work with on-chip memories and use the bus interface mainly for accessing
small external memories or for controlling external peripherals.
Two memory sizes are supported:
• 8-bit Multiplexed Bus: 2 KBytes
• Any other bus mode:
Memory model and bus mode are selected during reset by pin EA and PORT0 pins. For
further details about the external bus configuration and control please refer to
External word and byte data can only be accessed via indirect or long 16-bit addressing
modes using one of the four DPP registers. There is no short addressing mode for
external operands. Any word data access is made to an even byte address.
For PEC data transfers the external memory in segment 0 can be accessed
independently of the contents of the DPP registers via the PEC source and destination
pointers.
The external memory is not provided for single bit storage and therefore it is not
bitaddressable.
1)
User’s Manual
This bus mode offers lowest performance but allows concurrent operation of external bus interface and
standard serial interfaces.
External Memory Space
64 KBytes
with address and data on PORT0 (Default after Reset)
with address and data on PORT0/P0L
with address on PORT1 and data on P0L
with A10 … A0 on PORT0
with A15 … A0 on PORT0 or PORT1
3-9
Memory Organization
1)
C164CM/C164SM
Derivatives
V1.0, 2002-02
Chapter
9.