![Infineon Technologies TC1796 Скачать руководство пользователя страница 320](http://html1.mh-extra.com/html/infineon-technologies/tc1796/tc1796_user-manual_2055437320.webp)
TC1796
System Units (Vol. 1 of 2)
On-Chip System Buses and Bus Bridges
User’s Manual
6-27
V2.0, 2007-07
Buses, V2.0
Transactions on the FPI Bus are classified via a 4-bit operation code (see
Note that split transactions (OPC = 1000
B
to 1110
B
) are not used in the TC1796.
6.5.3
Clock Management
The BCU can be configured so that it shuts down automatically when not needed by
disabling its internal clock. When it is needed again, for instance when a bus request
signal is received from a master, the BCU will enable its clock and perform the
arbitration. If no further bus activity is required after the transfer has completed, the BCU
will automatically shut off its clock and return to idle mode.
Automatic power management is controlled through the xBCU_CON.PSE bit. When
cleared to 0, power management is disabled, and the BCU clock is always active. This
might be required, for instance, to debug both the active and idle FPI Bus states of an
application via an external emulator or other debugging hardware.
Table 6-11
FPI Bus Master TAG Assignments
TAG-Number
FPI Bus
Description
1001
B
SPB
Peripheral Control Processor (PCP2)
1010
B
DMA Controller
1011
B
LFI Bridge
1100
B
OCDS (Cerberus)
1111
B
RPB
DMA Controller
Others
–
Reserved
Table 6-12
FPI Bus Operation Codes (OPC)
OPC
Description
0000
B
Single Byte Transfer (8-bit)
0001
B
Single Half-Word Transfer (16-bit)
0010
B
Single Word Transfer (32-bit)
0100
B
2-Word Block Transfer
0101
B
4-Word Block Transfer
0110
B
8-Word Block Transfer
1111
No operation
0011
B
, 0111
B
, 1000
B
- 1110
B
Reserved