Hitachi SH7760 Solution Engine2 Overview page 55

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6.2.6 Power Supply Control Register Write Procedure

This subsection describes the procedure for writing to a controller control of the power supply controller from

SH7760.

(1) SH7760 issues a write command to the power supply controller.

(2) The power supply controller returns a response the SH7760.

[Note]

(1) Don't issue multiple commands continually from SH7760. Note that the next command must be issued after a

response to the preceding command has been returned from the power supply controller.

6.2.7

Write Command

Figure 6.7 shows the write command format. SH7760 sends a start code, a function code, a register address and

data, in this order, as a write command.

(1) Start code

This code is fixed at 0x20.

(2) Function code

• A 1-byte function code specifies the size of data to be written in the lower 4 bits when the upper 4 bits of a

function code are 1100. Figure 6.3 shows a function command where the upper 4 bits are 1100.

• A 2-byte function code specifies the size of data to be written in the lower 12 bits when the upper 4 bits of a

function code are 1101. Figure 6.9 shows a function command where the upper 4 bits are 1101.

D15

D14

(3) Register Address

The register address specifies the address of the register to be written.

(4) Data

This field specifies the size of data to be written. This data size is equal to that specified in the function code.

(2) Function code

(1 byte)

(1 byte or 2 byte)

Figure 6.8 Function Command (1 Byte)

D13

D12

D11

D10

Figure 6.9 Function Command (2 Byte)

Figure 6.7 Read Command

Size of data

(3) Register address

(2byte)

(4) Data

(N byte)

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