ARM7EJ-S Technical Reference Manual 5.15.2. Connecting multiple coprocessors

5.15.2. Connecting multiple coprocessors

If you have multiple coprocessors in your system, you must connect the following coprocessor outputs to all coprocessors present in your system:

CPCLKEN
CPINSTR
CPDOUT
CPTBIT
CPJBIT
CPnMREQ
CPnTRANS
CPPASS
CPLATECANCEL.

You must connect the coprocessor inputs as shown in Table 5.2.

Table 5.2. Coprocessor input signal connections

Name	Connection information
CPEN	Static signal that must be tied HIGH.
CHSD and CHSE	Combine the individual bit 1 of CHSD and CHSE by ANDing logically before connecting onto the ARM7EJ-S processor corresponding inputs. Combine the individual bit 0 of CHSD and CHSE by ORing logically before connecting onto the ARM7EJ-S processor corresponding inputs.
CPDIN	Multiplex the CPDIN data output of each coprocessor, or build an OR-tree between all CPDIN coprocessor outputs if CPDIN is driven LOW when the coprocessor is inactive, so that the ARM7EJ-S processor CPDIN input only receives the CPDIN value from the active coprocessor.

Name

Connection information

CPEN

Static signal that must be tied HIGH.

CHSD and CHSE

Combine the individual bit 1 of CHSD and CHSE by ANDing logically before connecting onto the ARM7EJ-S processor corresponding inputs.

Combine the individual bit 0 of CHSD and CHSE by ORing logically before connecting onto the ARM7EJ-S processor corresponding inputs.

CPDIN

Multiplex the CPDIN data output of each coprocessor, or build an OR-tree between all CPDIN coprocessor outputs if CPDIN is driven LOW when the coprocessor is inactive, so that the ARM7EJ-S processor CPDIN input only receives the CPDIN value from the active coprocessor.

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