SanDisk SD032 Manual descarregar pdf (Página 56)

Start bit

always '0'

Block length

End bt:

always '1'

Standard busy

(only DAT0 used):

MSB (4095)

0 CRC 1

LSB (0)

Start bit

always '0'

Block length /4

End bt:

always '1'

MSN

LSN

DAT3

0 4095 3 CRC 1

DAT2

0 4094 2 CRC 1

DAT1

0 4093 1 CRC 1

DAT0

0 4092 0 CRC 1

Wide bus (all four

data lines used):

Figure 4-6. Data Packet Format

4.2. Protocol’s Functional Description

All communication between the host and miniSD Cards is controlled by the host (master). The host sends the

following two types of commands:

• Broadcast Commands—Broadcast commands are intended for all miniSD Cards. Some of these

commands require a response.

• Addressed (Point-to-Point) Commands—The addressed commands are sent to the addressed

miniSD Card and cause a response to be sent from this card.

A general overview of the command flow is shown in Figure 5-7 for the Card Identification Mode and in Figure 5-8

for the Data Transfer Mode. The commands are listed in the command tables (Tables 4-3 through 4-10). The

dependencies between the current miniSD Card state, received command and following state are listed in

Table 4-21. In the following sections, the different card operation modes will be described first. Thereafter, the

restrictions for controlling the clock signal are defined. All miniSD Card commands together with the corresponding

responses, state transitions, error conditions and timings are presented in the following sections.

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SanDisk SD032 Manual Página 56