MPC852TADS Freescale Semiconductor, MPC852TADS Datasheet - Page 59

• Manufacturer Part Number: MPC852TADS
• Description: Networking Modules & Development Tools ADS BOARD FOR 852
• Manufacturer: Freescale Semiconductor
• Type: Network Controller & Processorr

Specifications of MPC852TADS

• Memory Type: Flash, SDRAM
• Interface Type: RS-232, Ethernet, PCMCIA
• Operating Voltage: 1.8 V to 3.3 V
• Operating Temperature Range: 0 C to + 30 C
• Board Size: 233 mm x 150 mm
• Product: Modules
• For Use With/related Products: MPC852T
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

47
4•8•1•1
Following power-up, the SDRAM needs to be initialized in the manner outlined below:
4•8•2
Refresh the SDRAM by using its auto-refresh mode. For example, the UPMB periodic timer issues a burst of four
auto-refresh commands to the SDRAM every 62.4 msec. As a result, all 2048 SDRAM rows are refreshed within a
specific 32.8 msec slot.
1)
2)
3)
4)
5)
6)
7)
8)
Program the UPMB with the values noted in
upto 32MHz" on page 32
- 50MHz" on page
Program the Memory Controller (MPTPR, MBMR, OR4 and BR4) registers as per
ory Controller Initializations For 20Mhz" on page 29
tion For 66Mhz with DRAM-EDO" on page
Set the MAR to the correct value (0x48 for up to 32MHz or 0x88 for 32-50 MHz).
Run the MRS command, programmed in locations five to eight of the UPMB, by writing the MCR with
0x80808105.
Change the MBMR TLFB field to eight in order to maintain 8-beat refresh bursts.
Run the refresh sequence (8 refresh cycles being performed) by writing the MCR with 0x80808130.
Restore the MBMR TLFB field to four in order to provide the 4-beat refresh bursts of normal operation.
The SDRAM is now initialized and ready for operation.
SDRAM Initializing Procedure
SDRAM Refresh
TABLE 4-9. SDRAM Mode Register Programming
Freescale Semiconductor, Inc.
Burst Length
Burst Type
CAS Latency
Write Burst Length
For More Information On This Product,
33.
SDRAM Option
or in
Go to: www.freescale.com
Functional Description
TABLE 3-10. "UPMB Initialization for KS643232C-TC60, 32+MHz
MPC852TADS - User’s Manual
TABLE 3-9. "UPMB Initialization for KS643232C-TC60
Sequential
50MHz
Burst
24.
Value @ Frequency
4
2
or
TABLE 3-4. "Memory Controller Initializa-
Sequential
25MHz
Burst
4
1
TABLE 3-7. "Mem-
Release 1.0