S3C2416X RISC MICROPROCESSOR
STATIC MEMORY CONTROLLER
5-11
3.6 BUS
TURNAROUND
You can configure the SMC for each memory bank to use external bus turnaround cycles between read and write
memory accesses. You can program the IDCY field for up to 15 bus turnaround wait states. This avoids bus
contention on the external memory data bus. Bus turnaround cycles are generated between external bus transfers
as follows:
read-to-read, to different memory banks
read-to-write to the same memory banks
read-to-write to different memory banks
Figure 5-12 shows a zero wait asynchronous read followed by two zero wait asynchronous writes with two
turnaround cycles added. The standard minimum of two AHB wait states are added to the read transfer, one is
added to the first write, as for any read-write transfer sequence, and three are added to the second write because
of insertion of the two turnaround cycles that are only generated after the first write transfer has been detected,
and the standard one wait state added when a write transfer is buffered.
Turnaround Cycles
A
B
C
D(A)
D(B)
D(C)
SMCLK
ADDR
nOE
nWE
nCS
DATA(IN)
DATA(OUT)
IDCY=2
Figure 5-12. Read, then two Writes (WSTRD=WSTWR=0), Two Turnaround Cycles (IDCY=2)
Содержание S3C2416
Страница 33: ...S3C2416X RISC MICROPROCESSOR PRODUCT OVERVIEW 1 5 3 BLOCK DIAGRAM Figure 1 1 S3C2416X Block Diagram ...
Страница 38: ...PRODUCT OVERVIEW S3C2416X RISC MICROPROCESSOR 1 10 153 AIN 1 U14 195 EINT 10 GPG2 K15 237 SDATA 14 C18 ...
Страница 122: ...BUS MATRIX EBI S3C2416X RISC MICROPROCESSOR 3 4 NOTES ...
Страница 204: ...DMA CONTROLLER S3C2416X RISC MICROPROCESSOR 8 18 NOTES ...
Страница 284: ...WATCHDOG TIMER S3C2416X RISC MICROPROCESSOR 11 6 NOTES ...
Страница 320: ...REAL TIME CLOCK S3C2416X RISC MICROPROCESSOR 13 16 NOTES ...
Страница 344: ...UART S3C2416X RISC MICROPROCESSOR 14 24 NOTES ...
Страница 380: ...USB2 0 DEVICE S3C2416X RISC MICROPROCESSOR 16 34 NOTES ...
Страница 432: ...2D S3C2416X RISC MICROPROCESSOR 18 38 NOTES ...
Страница 446: ...HS_SPI CONTROLLER S3C2416X RISC MICROPROCESSOR 19 14 NOTES ...
Страница 455: ...S3C2416X RISC MICROPROCESSOR HSMMC CONTROLLER 20 9 4 9 SD COMMAND ISSUE SEQUENCE Figure 20 9 Timeout Setting Sequence ...
Страница 604: ...S3C2416X RISC MICROPROCESSOR S3C2416X RISC MICROPROCESSOR 23 22 NOTES ...
Страница 638: ...PCM AUDIO INTERFACE S3C2416X RISC MICROPROCESSOR 25 18 NOTES ...
Страница 653: ...S3C2416X RISC MICROPROCESSOR ELECTRICAL DATA 26 15 Figure 26 14 SDRAM READ WRITE Timing Trp 2 Trcd 2 Tcl 2 DW 16 bit ...
Страница 670: ...ELECTRICAL DATA S3C2416X RISC MICROPROCESSOR 26 32 NOTES ...
Страница 672: ...MECHANICAL DATA S3C2416X RISC MICROPROCESSOR 30 2 Figure 27 2 330 FBGA 1414 Package Dimension 2 Bottom View ...