st20-gp6 STMicroelectronics, st20-gp6 Datasheet - Page 108

• Manufacturer Part Number: st20-gp6
• Description: Gps Processor
• Manufacturer: STMicroelectronics

ST20-GP6
20 Timing specifications
20.1 EMI timings
The ‘Reference Clock’ used in the EMI timings is a virtual clock and is defined as the point at which
all EMI strobe and address outputs programmed to change at the start of a memory cycle have
become valid. This is designed to remove process dependent skews from the datasheet descrip-
tion and highlight the dominant influence of address and strobe timings on memory system design.
Notes:
108/123
1
2
MemReadnotWrite strobe — not applicable as it does not change state mid cycle.
Timed relative to the end of the access cycle. There could be many clocks in the access
cycle, and the strobes may be programmed to go inactive at a previous clock cycle.
t
Symbol Parameter
t
t
t
t
t
t
t
t
SVRDX
CHAV
CLSV
CHSV
RDVCH
CHRDX
CHWDV
WVCH
CHWX
Reference clock high to Address valid
Reference clock low to Strobe valid
Reference clock high to Strobe valid
Read Data valid to Reference clock high
Read Data hold after Reference clock high
Read Data hold after Strobe valid
Reference clock high to Write Data valid
MemWait valid to Reference clock high
MemWait hold after Reference clock high
Table 20.1 EMI cycle timings
Min
-11
10
20
-9
-9
0
0
0
Max
0
3
0
2
Units Notes
ns
ns
ns
ns
ns
ns
ns
ns
ns
1
2
2