ST10F166 datasheet(9/62 Pages) STMICROELECTRONICS

9 / 62 page

ST10F166

9/62

3 EXTERNAL BUS CONTROLLER

All external memory accesses are performed by the on-chip External Bus Controller

(EBC). During Reset, it can be programmed to either the Single Chip Mode when no

external memory is required, or to one of four different external memory access

modes, which are as follow:

16/18 bit Addresses, 8 bit Data, Demultiplexed

16/18 bit Addresses, 8 bit Data, Multiplexed

16/18 bit Addresses, 16 bit Data, Demultiplexed

16/18 bit Addresses, 16 bit Data, Multiplexed

In the demultiplexed bus mode, Port 1 is used as an output for addresses and Port 0

is used as an input/output for data. In the multiplexed bus modes, one of the two 16

bit ports, Port 0, is used as an input/output for both addresses and data.

For applications which require less than 64 Kbytes of memory space, a non-segment-

ed memory model can be selected. During the initialization phase, the bus configura-

tion and mapping of the Flash Memory to segment 1 may be programmed. After the

EINIT instruction, only the external bus configuration can be changed at any time.

In this case,all memory locations can be addressed by 16 bits, and thus port 4 is not

needed as an output for the two significant address biss (A17 and A16, as is the case

when using the segmented memory model.

ST10F166 데이터시트(PDF) 9 Page - STMicroelectronics