4 local bus sdram mode register (lsdmr), Local bus sdram mode register (lsdmr) -24, Lsdmr field descriptions -24 – Motorola MPC8260 User Manual
Page 300: Section 10.3.4, Able 10-8
10-24
MPC8260 PowerQUICC II UserÕs Manual
MOTOROLA
Part III. The Hardware Interface
10.3.4 Local Bus SDRAM Mode Register (LSDMR)
The LSDMR, shown in Figure 10-10, has the same Þelds as the PSDMR. Table 10-8
describes LSDMR Þelds.
Table 10-8. LSDMR Field Descriptions
Bits
Name
Description
0
PBI
Page-based interleaving. Selects the address multiplexing method. PBI works in conjunction
with ORx[SDA10]. See Section 10.4.5, ÒBank Interleaving.Ó
0 Bank-based interleaving
1 Page-based interleaving (normal operation)
1
RFEN
Refresh enable. Indicates that the SDRAM requires refresh services.
0 Refresh services are not required
1 Refresh services are required
2Ð4
OP
SDRAM operation. Selects the operation that occurs when the SDRAM device is accessed.
000 Normal operation
001 CBR refresh, used in SDRAM initialization.
010 Self refresh (for debug purpose).
011 Mode Register write, used in SDRAM initialization.
100 Precharge bank (for debug purpose).
101 Precharge all banks, used in SDRAM initialization.
110 Activate bank (for debug purpose).
111 Read/write (for debug purpose).
5Ð7
SDAM
Address multiplex size. Determines how the address of the current memory cycle is output on
the address pins. See Section 10.4.5.1, ÒSDRAM Address Multiplexing (SDAM and BSMA).У
8Р10
BSMA
Bank select multiplexed address line. Selects which MPC8260 address pins serve as
bank-select address for the local bus SDRAM. See Section 10.4.5.1, ÒSDRAM Address
Multiplexing (SDAM and BSMA).Ó
000 L_A14 (ORx[BPD] must be 00)
001 L_AÐL_A15 (ORx[BPD] must be 00 or 01)
010 L_A14ÐL_A16
011 L_A15ÐL_A17
100 L_A16ÐL_A18
101 L_A17ÐL_A19
110 L_A18ÐL_A20
111 L_A19ÐL_A21
11Ð13
SDA10
ТA10У control. When SDRAM is selected, with ORx[PBI], determines which address line is
output to SDA10 during an
ACTIVATE
command, to control the memory access. See
Section 10.4.12.1, ÒSDRAM ConÞguration Example (Page-Based Interleaving).Ó
For PBI=0:
000 A12
001 A11
010 A10
011 A9
100 A8
101 A7
110 A6
111 A5
For PBI=1:
000 A10
001 A9
010 A8
011 A7
100 A6
101 A5
110 A4
111 A3