Motorola MPC8260 PowerQUICC II User Manual page 301

Table 10-8. LSDMR Field Descriptions (Continued)
Bits Name
14Ð16 RFRC Refresh recovery. DeÞnes the earliest timing for an activate command after a
command. Sets the refresh recovery interval in clock cycles. See Section 10.4.6.6, ÒRefresh
Recovery Interval (RFRC),Ó for how to set this Þeld.
000 Reserved
001 3 clocks
010 4 clocks
011 5 clocks
100 6 clocks
101 7 clocks
110 8 clocks
111 16 clocks
17Ð19 PRETOACT Precharge to activate interval. DeÞnes the earliest timing for
after a precharge command. See Section 10.4.6.1, ÒPrecharge-to-Activate Interval.Ó
001 1 clock-cycle wait states
010 2 clock-cycle wait states
...
111 7 clock-cycle wait states
000 8 clock-cycle wait states
20Ð22 ACTTORW Activate to read/write interval. DeÞnes the earliest timing for
ACTIVATE
001 1 clock cycle
010 2 clock cycles
...
111 7 clock cycles
000 8 clock cycles
23 BL Burst length
0 SDRAM burst length is 4. Use this value if the device port size is16
1 SDRAM burst length is 8. Use this value if the device port size is 32 or 8
24Ð25 LDOTOPRE Last data out to precharge. DeÞnes the earliest timing for
data was read from the SDRAM. See Section 10.4.6.4, ÒLast Data Out to Precharge.Ó
00 0 clock cycles
01 -1 clock cycle
10 -2 clock cycles
11 Reserved
26Ð27 WRC Write recovery time. DeÞnes the earliest timing for
written to the SDRAM. See Section 10.4.6.5, ÒLast Data In to PrechargeÑWrite Recovery.Ó
01 1 clock cycles
10 2 clock cycles
11 3 clock cycles
00 4 clock cycles
MOTOROLA
SDRAM DeviceÐSpeciÞc Parameters:
command. See Section 10.4.6.2, ÒActivate to Read/Write Interval.Ó
Chapter 10. Memory Controller
Part III. The Hardware Interface
Description
ACTIVATE
/
READ WRITE
PRECHARGE
command after the last data is
PRECHARGE
REFRESH
or command
REFRESH
command after an
command after the last
10-25