User’s Manual
C166S V1 SubSystem
Central Processing Unit
User’s Manual
3-39
V 1.6, 2001-08
3.4.6.4
Long Transfer Mode
1)
If the long transfer mode is enabled by the PT flag (PT = 1) in the PEC control register
PECCx, the PEC Transfer Count Field (COUNT2) of the PECXCx register directly
controls the action of the respective PEC channel.
The long transfer mode is only available for PEC channels with an even PEC number.
Note: The channel link mode is independent of the long transfer mode. Both modes can
be combined.
Note: The PEC Transfer Count Field (COUNT) of the PECCx register must be set to
zero.
Note: Crossing of segment boundaries is not checked during data transfers with long
transfer count, and is not supported. A wrap around occurs when reaching the
segment boundary .
The contents of the bitfield COUNT2 may specify a certain number of PEC transfers or
no PEC service at all. The 16-bit transfer counter permits servicing up to 65536 byte
transfers or up to 32768 word transfers.
a) If the PEC transfer counter COUNT2 value is set to 0000
H
, the normal interrupt
requests are processed instead of PEC data transfers, and the corresponding PEC
channel remains idle.
b) If the bitfield COUNT2 is set to service a specified number of requests by the
respective PEC channel, it is decremented with each PEC transfer and the request
flag is cleared to indicate that the request has been serviced. When COUNT2
reaches 0000
H
, it activates the ISR that has the same priority level (EOPINT = 0),
or triggers the EOP ISR with a different priority level (EOPINT = 1). When COUNT2
is decremented from 0001
H
to 0000
H
after a data transfer, the request flag will be
1)
The long transfer mode is an optional mode for PEC channels with an even number. Please refer to the product
User Manual.
PEC Extended Count Register
PECXC0/2/4/6
SFR (
H
,
H
)
(Reset value: 0000
H
)
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
COUNT2
rwh
Field
Bits
Type Description
COUNT2
[15:0]
rwh
PEC Extended (Long) Transfer Count
PEC transfer count extension (see table below)
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...
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