TC1784
On-Chip System Buses and Bus Bridges
User´s Manual
4-23
V1.1, 2011-05
Buses, V1.9
4.5.2
Bus Transaction Types
This section describes the SPB transaction types.
Single Transfers
Single transfers are byte, half-word, and word transactions that target any slave
connected to SPB. Note that the LFI Bridge operates as an SPB master.
Block Transfers
Block transfers operate in principle in the same way as single transfers do, but one
address phase is followed by multiple data phases. Block transfers can be composed of
2 word, 4 word, or 8 word transfers.
Note: In general, block transfers (2 word, 4 word, or 8 word) cannot be executed in the
TC1784 with peripheral units that operate as FPI Bus slaves during an FPI Bus
transaction.
Block transfers are initiated by the following CPU instructions: LD.D, LD.DA, MOV.D,
ST.D and ST.DA. The BCOPY instruction of the PCP also initiates a block transfer
transaction on the FPI Bus.
Atomic Transfers
Atomic transfers are generated by LDMST, ST.T and SWAP.W instructions that require
two single transfers. The read and write transfer of an atomic transfer are always locked
and cannot be interrupted by another bus masters. Atomic transfers are also referenced
as read-modify-write transfers.
Note: See also
for available FPI Bus transfer types.
4.5.3
Reaction of a Busy Slave
If an FPI Bus slave is busy at an incoming FPI Bus transaction request, it can delay the
execution of the FPI Bus transaction. The requesting FPI Bus master releases the
FPI Bus for one cycle after the FPI Bus transaction request, in order to allow the FPI Bus
slave to indicate if it is ready to handle the requested FPI Bus transaction. This sequence
is repeated as long as the slave indicates that it is busy.
Note: For the FPI Bus default master, the one cycle gap does not result in a performance
loss because it is granted the FPI Bus in this cycle as default master if no other
master requests the FPI Bus for some other reasons.
Summary of Contents for TC1784
Page 1: ...User s Manual V1 1 2011 05 Microcontrollers TC1784 32 Bit Single Chip Microcontroller ...
Page 3: ...User s Manual V1 1 2011 05 Microcontrollers TC1784 32 Bit Single Chip Microcontroller ...
Page 950: ...TC1784 Direct Memory Access Controller DMA User s Manual 11 132 V1 1 2011 05 DMA V3 03 ...
Page 1949: ...TC1784 General Purpose Timer Array GPTA v5 User s Manual 21 297 V1 1 2011 05 GPTA v5 V1 14 ...
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