S3C2500B
INSTRUCTION SET
3-51
3.14 COPROCESSOR DATA OPERATIONS (CDP)
The instruction is only executed if the condition is true. The various conditions are defined in Table 3-2. The
instruction encoding is shown in Figure 3-25.
This class of instruction is used to tell a coprocessor to perform some internal operation. No result is
communicated back to ARM9TDMI, and it will not wait for the operation to complete. The coprocessor could
contain a queue of such instructions awaiting execution, and their execution can overlap other activity, allowing
the coprocessor and ARM9TDMI to perform independent tasks in parallel.
3.14.1 COPROCESSOR INSTRUCTIONS
The S3C2500B, unlike some other ARM-based processors, does not have an external coprocessor interface. It
does not have a on-chip coprocessor also.
So then all coprocessor instructions will cause the undefined instruction trap to be taken on the S3C2500B. These
coprocessor instructions can be emulated by the undefined trap handler. Even though external coprocessor can
not be connected to the S3C2500B, the coprocessor instructions are still described here in full for completeness.
(Remember that any external coprocessor described in this section is a software emulation.)
31
24
27
19
15
Cond
CRm
28
16
11
12
23
20
[3:0] Coprocessor operand register
[7:5] Coprocessor information
[11:8] Coprocessor number
[15:12] Coprocessor destination register
[19:16] Coprocessor operand register
[23:20] Coprocessor operation code
[31:28] Condition Field
0
Cp
Cp#
CRd
CRn
1110
CP Opc
8 7
5 4 3
0
Figure 3-25. Coprocessor Data Operation Instruction
3.14.2 THE COPROCESSOR FIELDS
Only bit 4 and bits 24 to 31 are significant to ARM9TDMI. The remaining bits are used by coprocessors. The
above field names are used by convention, and particular coprocessors may redefine the use of all fields except
CP# as appropriate. The CP# field is used to contain an identifying number (in the range 0 to 15) for each
coprocessor, and a coprocessor will ignore any instruction which does not contain its number in the CP# field.
The conventional interpretation of the instruction is that the coprocessor should perform an operation specified in
the CP Opc field (and possibly in the CP field) on the contents of CRn and CRm, and place the result in CRd.
Summary of Contents for S3C2500B
Page 2: ...S3C2500B 32 BIT RISC MICROPROCESSOR USER S MANUAL Revision 1 ...
Page 17: ......
Page 25: ......
Page 80: ...PRODUCT OVERVIEW S3C2500B 1 46 NOTES ...
Page 296: ...MEMORY CONTROLLER S3C2500B 5 60 NOTES ...
Page 531: ...GDMA CONTROLLER S3C2500B 12 24 NOTES ...
Page 593: ...I O PORTS S3C2500B 15 12 NOTES ...