Power Supply Control Register Write Procedure; Write Command - Renesas SH7727 General Information Manual

R0P7727TH003TRKE General Information Manual

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
SH7727.
(1) SH7727 issues a write command to the power supply controller.
(2) The power supply controller returns a response the SH7727.
Don't issue multiple commands continually from SH7727. 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. SH7727 sends a start code, a function code, a register address
and data, in this order, as a write command.
(1) Start code
(1 byte)
(1) Start code
This code is fixed at 0x02.
(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 6.8 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
1
(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 or 2 byte)
Figure 6.7 Read Command
D7 D6 D5
1 1
Figure 6.8 Function Command (1 Byte)
D13 D12 D11 D10
1 0 1
Figure 6.9 Function Command (2 Bytes)
CAUTION
(3) Register address
(2 byte)
D4 D3 D2 D1 D0
0 0 Size of data
D9 D8 D7 D6
Size of data
46
Power Supply Controller
(4) Register address
(N byte)
D5 D4 D3 D2 D1 D0