SMC032BFY6 datasheet(72/91 Pages) STMICROELECTRONICS

72 / 91 page

CF-ATA command description

SMCxxxBF

72/91

10.16

Seek (7Xh)

This command is effectively a NOP command to the Card although it does perform a range

check of cylinder and head or LBA address and returns an error if the address is out of

range. Table 67 shows the Seek command Byte sequence.

10.17

Set Features (EFh)

This command is used by the host to establish or select certain features. Table 68 shows the

Set Features command Byte sequence. Table 69 defines all features that are supported.

●

Features 01h and 81h are used to enable and clear 8 bit data transfer modes in True

IDE Mode. If the 01h feature command is issued all data transfers will occur on the D7-

D0 data lines and the –IOIS16 signal will not be asserted for data register accesses.

The host must not enable this feature for DMA transfers.

●

Feature 03h allows the host to select the PIO or the Multi-Word DMA transfer mode.

The number of sectors to be transferred must be specified in the Sector Count register

(see Table 70 for values). The upper 5 bits define the type of transfer and the lower 3

bits encode the transfer mode. Only one PIO mode and one Multi-Word mode can be

selected at a time. The host can change the selected mode by issuing the Set Features

command.

●

Feature code 9Ah allows the host to configure the Card to best meet the host system

power requirements. The host programs the Sector Count register to a value that is

equal to one-fourth of the desired maximum average current (in mA) that the Card

should consume. For example, if the Sector Count register is set to ‘6’, the Card must

be configured to provide the best possible performance without exceeding 24 mA.

Upon completion of the command, the Card replies to the host with the range of values

that it supports. The minimum value is set in the Cylinder Low Register, and the

maximum value is set in the Cylinder Hi register. After power-up, the Card defaults to

operate at the highest performance and therefore in the highest current mode. Values

outside this programmable range are accepted by the card. However, the Card will

operate either at the lowest power or highest performance as appropriate.

Table 67.

Seek

Bit

3210

Command (7)

7Xh

C/D/H (6)

LBA

Drive

Head (LBA 27-24)

Cyl High (5)

Cylinder High (LBA 23-16)

Cyl Low (4)

Cylinder Low (LBA 15-8)

Sect Num (3)

X (LBA 7-0)

Sect Cnt (2)

Feature (1)

SMC032BFY6 Datasheet(PDF) 72 Page - STMicroelectronics

SMC032BFY6 Datasheet(HTML) 72 Page - STMicroelectronics

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

Datasheet Download

Link URL