Chapter 23 Notes on Use of TMPR4937
23-4
In the case only one channel is used, restarting DMS transfer without a reset of FIFO results in a
malfunction when the conditions (1) to (3) are satisfied.
When two channels are used in a system, the following table shows settings to cause malfunctions.
Ch. A of a bus error
Ch. B
FIFO XFSZ Transfer FIFO XFSZ Transfer
Transfer restarted
in ch. A after a bus
error (without reset
of FIFO)
Ch. B after a bus
error
Disable
Any
value
Single Disable
Any
value
Single
Malfunction of ch. A
Malfunction of ch. B
Disable
Any
value
Single
Enable
<4DW
Single
Malfunction of ch. A
Malfunction of ch. B
Disable
Any
value
Single Enable
≥
4DW Burst
1)
Malfunction of ch. A
Correct operation of
ch. B
1)
1) By this setting, Channel B performs burst transfer. When the different off-set values are set to the
source address and destination address of Channel B, or source and destination burst inhibit bits
are set, single and burst transfer modes are combined for data transfer, but a malfunction does
not occur.
<Supplemental information> Dual address transfer mode
– Single transfer:
Disable FIFO (DMMCR.FIFUM[n]=0]
or the value smaller than 4DW is set to DMCCRn.XFSZ.
– Burst transfer:
Enable FIFO (DMMCR.FIFUM[n]=1]
and 4DW or larger value is set to DMCCRn.XFSZ.
[Workarounds]
Workarounds vary depending on which type of dual address transfer is performed together with dual
address single transfer. Combination of 4 channels in DMAC0 or DMAC1 affects a workaround to be
required.(DMAC0 and DMAC1 are independent controllers.)
Single Transfer
Burst Transfer
Workaround
(1)
1 ch.
Null
(a) or (b)
(2)
1 ch.
1 to 3 ch.
(b)
(3)
2 to 4 ch.
Null
(a)
(4)
2 to 3 ch.
1 to 2 ch.
(a)
(a)
Enable FIFO for all channels that perform single transfer.
(DMMCRn.FIFUM[n]=1: n=3 to 0)
(b) After all channels finished transfers, set 1 to RSFIF in DMMCRn, then write 0 to reset and
release reset of FIFO.
Summary of Contents for TX49 TMPR4937
Page 1: ...64 Bit TX System RISC TX49 Family TMPR4937 Rev 2 0 ...
Page 4: ......
Page 13: ...Table of Contents ix TMPR4937 Revision History 1 ...
Page 14: ...Table of Contents x ...
Page 15: ...Handling Precautions ...
Page 16: ......
Page 18: ...1 Using Toshiba Semiconductors Safely 1 2 ...
Page 40: ...3 General Safety Precautions and Usage Considerations 3 18 ...
Page 42: ...4 Precautions and Usage Considerations 4 2 ...
Page 43: ...TMPR4937 2005 3 Rev 2 0 ...
Page 44: ......
Page 52: ...Chapter 1 Overview and Features 1 6 ...
Page 156: ...Chapter 7 External Bus Controller 7 56 ...
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Page 492: ...Chapter 16 Removed 16 2 ...
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Page 506: ...Chapter 20 Extended EJTAG Interface 20 8 ...
Page 530: ...Chapter 22 Pinout and Package Information 22 10 ...
Page 542: ...Chapter 24 Parts Number when Ordering 24 2 ...