
M E M O R Y C O N T R O L L E R
Asynchronous page mode read
214
Hardware Reference NS9215
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
A s y n c h r o n o u s p a g e m o d e r e a d
The memory controller supports asynchronous page mode read of up to four
memory transfers by updating address bits addr[1] and addr[0]. This feature
increases the bandwidth by using a reduced access time for the read accesses that
are in page mode. The first read access takes static wait read and
WAITRD
cycles.
Subsequent read accesses that are in page mode take static wait page and
WAITPAGE
cycles. The chip select and output enable lines are held during the burst, and only
the lower two address bits change between subsequent accesses. At the end of the
burst, the chip select and output enable lines are deasserted together.
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
A s y n c h r o n o u s p a g e m o d e r e a d : T i m i n g a n d p a r a m e t e r s
This section shows asynchronous page mode read timing diagrams and parameters.
External memory
page mode read
transfer
ThIs diagram shows an external memory page mode read transfer with two initial
wait states and one sequential wait state. The first read requires five AHB
arbitration cycles (plus three wait states); the following (up to 3) sequential
transfers have only one AHB wait state. This gives increased performance over the
equivalent nonpage mode ROM timing.
Timing parameter
Value
WAITRD
2
WAITOEN
0
WAITPAGE
N/A
WAITWR
N/A
WAITWEN
N/A
WAITTURN
N/A
A+8
A
A+4
D(A)
D(A+4)
clk_out
addr
data
cs[n]
st_oe_n
Содержание NS9215
Страница 1: ...NS9215 Hardware Reference 90000847_C Release date 10 April 2008...
Страница 3: ......
Страница 4: ......
Страница 26: ...26 Hardware Reference NS9215...
Страница 44: ...P I N O U T 26 5 System clock 44 Hardware Reference NS9215 System clock drawing...
Страница 52: ...P I N O U T 26 5 Power and ground 52 Hardware Reference NS9215...
Страница 80: ...I O C O N T ROL M O D U L E Memory Bus Configuration register 80 Hardware Reference NS9215...
Страница 136: ...WOR KI N G W I TH T H E C P U Noncachable instruction fetches 136 Hardware Reference NS9215...
Страница 202: ...S Y S T E M C O N T RO L M OD U L E RTC Module Control register 202 Hardware Reference NS9215...
Страница 260: ...M E MO R Y C O N T ROL L E R StaticMemory Turn Round Delay 0 3 registers 260 Hardware Reference NS9215...
Страница 354: ...E X T E R N A L D M A DMA Peripheral Chip Select register 354 Hardware Reference NS9215...
Страница 362: ...A E S D AT A E N C R Y P T I O N D E C R Y P T I O N M O D U L E CCM mode 362 Hardware Reference NS9215...
Страница 384: ...I O HU B M OD UL E Module Direct Mode TX Data Last FIFO 384 Hardware Reference NS9215 31 March 2008...
Страница 414: ...S E R I A L C ON T RO L M O D U L E U ART UART Modem Status register 414 Hardware Reference NS9215...
Страница 446: ...S E R I A L C ON T RO L M O D U L E S PI SPI timing characteristics 446 Hardware Reference NS9215...
Страница 472: ...R E A L TI M E C L O C K M O D U L E General Status register 472 Hardware Reference NS9215...
Страница 512: ...TI M I NG Clock timing 512 Hardware Reference NS9215...
Страница 514: ...PA CKA GING Processor Dimensions 514 Hardware Reference NS9215 P r o c e s s o r D i m e n s i o n s...
Страница 515: ...PA CKA GING Processor Dimensions www digiembedded com 515...
Страница 516: ...PA CKA GING Processor Dimensions 516 Hardware Reference NS9215...