Chapter 22 Electrical Characteristics
22-9
Note:
(1)
DMAREQ[n]
Edge Detection: Set the pulse width to 1.1
×
the GBUSCLK cycle or higher.
Level Detection: There is no AC characteristic definition. Continue asserting DMAREQ[1:0]
until DMAACK[1:0] is received.
(2)
DMAACK[n]
The DMAACK[n] signal is synchronous to SDCLK. (It is driven by GUBSCLK inside the chip.
See Chapter 6 for more information.)
The DMAACK[n] signal is asserted by SYSCLK or SDCLK for 3 cycles or more. However, this
is changed by the conditions [1] and [2] below.
[1] DMAC transfer mode (Single Address transfer, Dual Address transfer)
[2] Access time of the device DMAC accesses
•
When driving an external device with SYSCLK
Is asserted by SYSCLK for at least 3 cycles even in the shortest assertion case.
•
When driving an external device with SDCLK
Is asserted by SDCLK for at least 3 cycles even in the shortest assertion case. The AC
characteristics for Single Address transfer with SDRAM are tight, so we do not
recommend Single Address transfer.
(3)
DMADONE
*
Is asserted for only 1 SYSCLK cycle synchronous to SYSCLK.
Assertion Time
SDCLK[n]
DMAACK[n]
Summary of Contents for TMPR4925
Page 1: ...64 Bit TX System RISC TX49 Family TMPR4925 Rev 3 0 ...
Page 4: ......
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: ...TMPR4925 ...
Page 44: ......
Page 54: ...Chapter 1 Features 1 8 ...
Page 58: ...Chapter 2 Block Diagram 2 4 ...
Page 88: ...Chapter 4 Address Mapping 4 12 ...
Page 226: ...Chapter 8 DMA Controller 8 58 ...
Page 260: ...Chapter 9 SDRAM Controller 9 34 ...
Page 480: ...Chapter 15 Interrupt Controller 15 32 ...
Page 554: ...Chapter 19 Real Time Clock RTC 19 8 ...
Page 555: ...Chapter 20 Removed 20 1 20 Removed ...
Page 556: ...Chapter 20 Removed 20 2 ...
Page 564: ...Chapter 21 Extended EJTAG Interface 21 8 ...
Page 580: ...Chapter 22 Electrical Characteristics 22 16 ...
Page 588: ...Chapter 24 Usage Notes 24 2 ...