
SDRAM Controller (SDRAMC)
Freescale Semiconductor
18-17
18.4.3
SDRAM Configuration Register 1 (SDCFG1)
The 32-bit read/write SDRAM configuration register 1 (SDCFG1) stores necessary delay values between
specific SDRAM commands. During initialization, software loads values to the register according to the
selected SD_CLK frequency and SDRAM information obtained from the data sheet. This register resets
only by a power-up reset signal.
The read and write latency fields govern the relative timing of commands and data and must be exact
values. All other fields govern the relative timing from one command to another; they have minimum
values, but any larger value is also legal (but with decreased performance).
The minimum values of certain fields can be different for SDR, DDR SDRAM, even if the data sheet
timing is the same, because:
•
In SDR mode, the memory controller counts the delay in SD_CLK
•
In DDR mode, the memory controller counts the delay in 2 x SD_CLK (also referred to as
SD_CLK2)
•
SD_CLK—memory controller clock—is the speed of the SDRAM interface and is equal to the
internal bus clock.
•
SD_CLK2—double frequency of SD_CLK—DDR uses both edges of the bus-frequency clock
(SD_CLK) to read/write data
NOTE
In all calculations for setting the fields of this register, convert time units to
clock units and round up to the nearest integer.
1
IPALL
Initiate precharge all command. Used to force a software-initiated precharge all command. This bit is write-only,
reads return zero.
0 Do not generate a precharge command.
1 Generate a precharge all command. All SD_CSn signals are asserted simultaneously. SDCR[CKE] must be
set before generating a software precharge command.
Note: Software precharge is only possible when MODE_EN is set.
Note: Do not set IREF and IPALL at the same time.
0
Reserved, should be cleared.
Table 18-8. SDCR Field Descriptions (continued)
Field
Description
MCF5329 Reference Manual, Rev 3
Содержание MCF5329
Страница 106: ...ColdFire Core 3 32 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Страница 126: ...Enhanced Multiply Accumulate Unit EMAC 4 20 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Страница 148: ...Cache 5 22 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Страница 154: ...Static RAM SRAM 6 6 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Страница 184: ...Power Management 8 18 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Страница 204: ...Reset Controller Module 10 8 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Страница 220: ...System Control Module SCM 11 16 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Страница 228: ...Crossbar Switch XBS 12 8 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Страница 268: ...General Purpose I O Module 13 40 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Страница 392: ...SDRAM Controller SDRAMC 18 30 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Страница 436: ...Fast Ethernet Controller FEC 19 44 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Страница 564: ...Liquid Crystal Display Controller LCDC 22 44 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Страница 594: ...FlexCAN 23 30 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Страница 678: ...Pulse Width Modulation PWM Module 26 22 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Страница 684: ...Watchdog Timer Module 27 6 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Страница 692: ...Programmable Interrupt Timers PIT0 PIT3 28 8 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Страница 704: ...DMA Timers DTIM0 DTIM3 29 12 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Страница 720: ...Queued Serial Peripheral Interface QSPI 30 16 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Страница 754: ...UART Modules 31 34 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Страница 770: ...I2 C Interface 32 16 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Страница 790: ...Message Digest Hardware Accelerator MDHA 33 20 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Страница 866: ...Debug Module 36 50 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Страница 902: ...Register Memory Map Quick Reference A 26 Freescale Semiconductor MCF5329 Reference Manual Rev 3...