ELANSC520 datasheet(110/440 Pages) AMD

110 / 440 page

ROM/Flash Controller Registers

9-2

Élan™SC520 Microcontroller Register Set Manual

BOOTCS Control (BOOTCSCTL)

Memory-Mapped

MMCR Offset 50h

This register contains configuration information about the location (i.e., SDRAM bus or GP bus), width, operation

mode, and timing of the boot ROM that is attached to the ÉlanSC520 microcontroller BOOTCS signal.

Bit Definitions

Bit

Reserved

DGP

WIDTH[1–0]

MODE

Reserved

Reset

000???00

R/W

RSV

R/W

RSV

Bit

Reserved

SUB_DLY[1–0]

Reserved

FIRST_DLY[2–0]

Reset

00110111

R/W

RSV

R/W

RSV

R/W

Bit

Name

Function

–13

Reserved

This bit field should be written to 0 for normal system operation

DGP

BOOTCS Device SDRAM/GP Bus Select

This bit reflects the location of the boot ROM device that is enabled with the BOOTCS signal.

This bit’s value is latched from the CFG2 pinstrap when the PWRGOOD pin is asserted. The

ROM can be connected to either the SDRAM data bus or to the GP bus.

0 = ROM is on the GP bus.

1 = ROM is on the SDRAM data bus.

–10

WIDTH[1–0]

BOOTCS Device Width Select

This bit field reflects the width of the boot ROM. This bit field’s value is latched from the

CFG1

–CFG0 pinstraps when the PWRGOOD pin is asserted.

00 = ROM is 8 bits wide.

01 = ROM is 16 bits wide.

10 = ROM is 32 bits wide.

11 = ROM is 32 bits wide (same as 10b).

9MODE

BOOTCS Device Mode

This bit is used to configure the mode of the boot ROM device.

0 = ROM is non-page mode.

1 = ROM is page mode.

–6

Reserved

This bit field should be written to 0 for normal system operation

–4

SUB_DLY[1–0]

BOOTCS Device Delay for Subsequent Access

This bit field is used to configure the number of wait states for all page-mode accesses to the

ROM that are subsequent to the first access. This bit field applies only if the MODE bit is 1.

00 = 0 wait states

01 = 1 wait state

10 = 2 wait states

11 = 3 wait states

ELANSC520 Datasheet(PDF) 110 Page - Advanced Micro Devices

ELANSC520 Datasheet(HTML) 110 Page - Advanced Micro Devices

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 ...More

Datasheet Download

Link URL