Section, Page No. Changes
Errata to MPC8379E PowerQUICC II Pro Integrated Host
Processor Family Reference Manual, Rev. 1
14 Freescale Semiconductor
MA[14:0] O Address bus. Memory controller outputs for the address to the DRAM. MA[14:0] carry 15 of the address
bits for the DDR memory interface corresponding to the row and column address bits. MA0 is the lsb of
the address output from the memory controller.
State
Meaning
Asserted/Negated—Represents the address driven by the DDR memory controller. Contains
different portions of the address depending on the memory size and the DRAM
command being issued by the memory controller. See
Table 9-40 Table 9-41 for a
c
omplete description of the mapping of these signals.
Timing Assertion/Negation—The address lines are only driven when the controller has a command
scheduled to issue on the address/CMD bus; otherwise they will be at high-Z. It is valid
when a transaction is driven to DRAM (when MCSn is active).
High impedance—When the memory controller is disabled
MBA[2:0] O Logical bank address. Outputs that drive the logical (or internal) bank address pins of the SDRAM. Each
SDRAM supports four or eight addressable logical sub-banks. Bit zero of the memory controller’s output
bank address must be connected to bit zero of the SDRAM’s input bank address. MBA0, the
least-significant bit of the three bank address signals, is asserted during the mode register set command
to specify the extended mode register.
State
Meaning
Asserted/Negated—Selects the DDR SDRAM logical (or internal) bank to be activated during
the row address phase and selects the SDRAM internal bank for the read or write
operation during the column address phase of the memory access. Table 9-40
Table 9-41 describes the mapping of these signals in all cases.
Timing Assertion/Negation—Same timing as MAn
High impedance—Same timing as MAn
MCAS O Column address strobe. Active-low SDRAM address multiplexing signal. MCAS is asserted for read or
write transactions and for mode register set, refresh, and precharge commands.
State
Meaning
Asserted—Indicates that a valid SDRAM column address is on the address bus for read and
write transactions. See Table 9-48 for more information on the states required on MCAS
for various other SDRAM commands.
Negated—The column address is not guaranteed to be valid.
Timing Assertion/Negation—Assertion and negation timing is directed by the values described in
Section 9.4.1.4, “DDR SDRAM Timing Configuration 0 (TIMING_CFG_0),”
Section 9.4.1.5, “DDR SDRAM Timing Configuration 1 (TIMING_CFG_1),”
Section 9.4.1.6, “DDR SDRAM Timing Configuration 2 (TIMING_CFG_2),” and
Section 9.4.1.3, “DDR SDRAM Timing Configuration 3 (TIMING_CFG_3).”
High impedance—MCAS is always driven unless the memory controller is disabled.
MRAS O Row address strobe. Active-low SDRAM address multiplexing signal. Asserted for activate commands.
In addition; used for mode register set commands and refresh commands.
State
Meaning
Asserted—Indicates that a valid SDRAM row address is on the address bus for read and
write transactions. See Table 9-48 for more information on the states required on MRAS
for various other SDRAM commands.
Negated—The row address is not guaranteed to be valid.
Timing Assertion/Negation—Assertion and negation timing is directed by the values described in
Section 9.4.1.4, “DDR SDRAM Timing Configuration 0 (TIMING_CFG_0),”
Section 9.4.1.5, “DDR SDRAM Timing Configuration 1 (TIMING_CFG_1),”
Section 9.4.1.6, “DDR SDRAM Timing Configuration 2 (TIMING_CFG_2),” and
Section 9.4.1.3, “DDR SDRAM Timing Configuration 3 (TIMING_CFG_3).”
High impedance—MRAS is always driven unless the memory controller is disabled.
Table 9-3. Memory Interface Signals—Detailed Signal Descriptions (continued)
Signal I/O Description