
T I M I N G
Memory Timing
496
Hardware Reference NS9215
Static RAM
asynchronous
page mode read,
WTPG = 1
WTPG = 1
WTRD = 2
If the PB field is set to 1, all four byte_lane signals will go low for 32-bit,
16-bit, and 8-bit read cycles.
The asynchronous page mode will read 16 bytes in a page cycle. A 32-bit bus
will do four 32-bit reads, as shown (3-2-2-2). A 16-bit bus will do eight 16-bit
reads (3-2-2-2-3-2-2-2) per page cycle, and an 8-bit bus will do sixteen 8-bit
reads (3-2-2-2-3-2-2-2-3-2-2-2-3-2-2-2) per page cycle. 3-2-2-2 is the example
used here, but the WTRD and WTPG fields can set them differently.
Notes:
1
The length of the first cycle in the page is determined by the WTRD field.
2
The length of the 2nd, 3rd, and 4th cycles is determined by the WTPG field.
3
This is the starting address. The least significant two bits will always be ‘00.’
4
The least significant two bits in the second cycle will always be ‘01.’
5
The least significant two bits in the third cycle will always be ‘10.’
6
The least significant two bits in the fourth cycle will always be ‘11.’
7
If the PB field is set to 0, the byte_lane signal will always be high during a read cycle.
8
Setting the BMODE (Burst mode) bit D02 in the static memory configuration register allows the
static output enable signal to toggle during bursts.
N ot e- 1
N o te- 2
N o te- 2
N o te- 2
M 24
M 2 3
M 28
M 2 7
M 20
M 1 9
M 18
M 18
M 1 7
M 26
M 2 5
M 2 6
M 2 5
N ote -3
N ote -4
N ot e- 5
No te- 6
N o te- 7
c l k _ ou t
d ata < 31: 0>
ad dr < 27: 0>
s t_c s _ n< 3: 0>
oe _n
by te _lan e< 3: 0>
Summary of Contents for NS9215
Page 1: ...NS9215 Hardware Reference 90000847_C Release date 10 April 2008...
Page 3: ......
Page 4: ......
Page 26: ...26 Hardware Reference NS9215...
Page 44: ...P I N O U T 26 5 System clock 44 Hardware Reference NS9215 System clock drawing...
Page 52: ...P I N O U T 26 5 Power and ground 52 Hardware Reference NS9215...
Page 80: ...I O C O N T ROL M O D U L E Memory Bus Configuration register 80 Hardware Reference NS9215...
Page 136: ...WOR KI N G W I TH T H E C P U Noncachable instruction fetches 136 Hardware Reference NS9215...
Page 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...
Page 354: ...E X T E R N A L D M A DMA Peripheral Chip Select register 354 Hardware Reference NS9215...
Page 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...
Page 512: ...TI M I NG Clock timing 512 Hardware Reference NS9215...
Page 515: ...PA CKA GING Processor Dimensions www digiembedded com 515...
Page 516: ...PA CKA GING Processor Dimensions 516 Hardware Reference NS9215...