CHAPTER 6 DMA FUNCTIONS (DMA CONTROLLER)
248
User’s Manual U14359EJ4V0UM
Figure 6-17. Timing of Access to SRAM, External ROM, and External I/O During DMA Flyby Transfer (1/2)
(a) SRAM
→
→
→
→
external I/O
TASW
T1
Address
Data
WAIT (input)
D0 to D15 (I/O)
IOWR (output)
IORD (output)
LWR/LCAS/LDQM (output)
UWR/UCAS/UDQM (output)
WE (output)
OE (output)
RD (output)
CSn/RASm (output)
BCYST (output)
A0 to A25 (output)
CLKOUT (output)
TF
TI
T2
When TASW and TI are inserted
T1
T2
TF
TW
DMAAKx (output)
Address
Data
LBE (output)
UBE (output)
Remarks 1.
The
circle
{
indicates the sampling timing.
2.
The broken lines indicate the high-impedance state.
3.
n = 0 to 7, m = 1, 3, 4, 6, x = 0 to 3