XA-H4 NXP Semiconductors, XA-H4 Datasheet - Page 38

• Manufacturer Part Number: XA-H4
• Description: The powerful 16-bit XA CPU core and rich feature set make the XA-H3 and XA-H4 devices ideal for high-performance real-time applications such as industrial control and networking
• Manufacturer: NXP Semiconductors

Philips Semiconductors
1999 Sep 24
Single-chip 16-bit microcontroller
RAS (CS)
CASH, CASL
NOTE:
It is the minimum high time (thus RAS inactive) between two DRAM bus cycles on the same RAS pin.
ClkOut
CASL
RAS
D[7:0]
WE
A
RAS and CAS terminate together. The active low portion of RAS can be programmed to last from 3 to 6 clock cycles.
The high portion of RAS after Refresh can be programmed to last from 2 to 4 clock cycles. See Chapter 3 of the XA-H4 User Manual.
ClkOut
RAS
t
RP
minimum is specified for each of the 5 individual RAS pins (CS_RAS[5:1])
t
t
CHSL
CHAV
t
CHSL
t
RAS ADDRESS
AVSL
t
CLRL
Figure 20. DRAM 16-Bit Write on 8-Bit Bus (FPM or EDO DRAMs)
t
CHAV
t
CHSL
t
DVSL
t
t
CHAH
CHSL
t
Figure 22. RAS Precharge Time
AVSL
LS Byte
CAS ADDRESS EVEN
Figure 21. REFRESH
t
CHSH
38
t
CHAH
t
CHAV
t
RP
t
CHSH
t
CPWH
t
DVSL
CAS ADDRESS ODD
MS Byte
t
t
CHSH
CHAH
t
CHAV
Preliminary specification
SU01288
SU01287
SU01289
XA-H4