User’s Manual
C166S V1 SubSystem
Central Processing Unit
User’s Manual
3-33
V 1.6, 2001-08
3.4.6.1
The PEC Source and Destination Pointers
The PEC channels’ source and destination pointers specify the locations between which
the data is to be moved. All pointers are 24 bits wide. The 24-bit source address is stored
in the internal DPRAM location SRCPx (lower 16 bits of address) and in the low byte of
register PECSNx (highest 8 address bits).
Figure 3-5
PEC Pointer Address Handling
The 24-bit destination address is stored in the DPRAM location DSTPx (lower 16 bits of
address) and in the high byte of register PECSNx (highest 8 address bits). Only the lower
16 bits of the PEC address pointers (segment offset) can be modified (incremented) by
the PEC transfer mechanism. The highest 8 bits, which represent the segment number,
are not modified by hardware. Therefore, the PEC pointers may be incremented within
the address space of one segment and may not cross the segment border. If the offset
address pointer has a value of FFFF
H
in the case of byte transfers (BWT = 1) or FFFE
H
in the case of word transfers (BWT = 0), the next increment will lead to an overflow. No
explicit error event is generated by the system in case of address pointer(s) overflow;
therefore, the user must prevent this condition from occurring.
0
15
SRCSNx
DSTSNx
PECSNx
0
15
DSTPx
DSTPx
0
15
SRCPx
SRCPx
0
Source Pointer
23
0
Destination Pointer
23
Segment Address
Segment Offset
Segment Address
Segment Offset
'DWD7UDQVIHU
16 15
16 15
8 7
x = 15...0, depending on PEC channel number
Содержание C166S V1 SubSystem
Страница 10: ...User s Manual C166S V1 SubSystem User s Manual I 6 V 1 6 2001 08...
Страница 16: ...User s Manual C166S V1 SubSystem Introduction User s Manual 1 6 V 1 6 2001 08...
Страница 126: ...User s Manual C166S V1 SubSystem Central Processing Unit User s Manual 3 96 V 1 6 2001 08...
Страница 178: ...User s Manual C166S V1 SubSystem Memory Organization User s Manual 4 52 V 1 6 2001 08...
Страница 206: ...User s Manual C166S V1 SubSystem Instruction Set User s Manual 5 28 V 1 6 2001 08...
Страница 306: ...User s Manual C166S V1 SubSystem Detailed Instruction Set User s Manual 6 100 V 1 6 2001 08...
Страница 362: ...User s Manual C166S V1 SubSystem The External Bus Interface User s Manual 8 40 V 1 6 2001 08...
Страница 452: ...User s Manual C166S V1 SubSystem General Purpose Timer Unit User s Manual 12 44 V 1 6 2001 08...
Страница 454: ...User s Manual C166S V1 SubSystem Instruction Index User s Manual 13 2 V 1 6 2001 08...
Страница 459: ......