Read Command - Renesas SH7727 General Information Manual

R0P7727TH003TRKE General Information Manual

6.2.3 Read Command

Figure 6.2 shows a read command format. SH7727 sends a start code, a function code and a register address,
in this order, as a read command.
(1) Start code (1 byte)
(1) Start code
The code is fixed at 0 x 02.
(2) Function code
• A 1-byte function code specifies the size of data to be read in the lower 4 bits when the upper 4 bits of
a function code are "1000" . Figure 6.3 shows a function command where the upper 4 bits are "1000" .
• A 2-byte function code specifies the size of data to be read in the lower 12 bits when the upper 4 bits
of a function code are "1001" .
Figure 6.4 shows a function command where the upper 4 bits are "1001" .
D15 D14
1
(3) Register Address
The register address specifies the address of the register to be read.
(2) Function code (1 byte or 2 bytes)
Figure6.2 Read Command
D7 D6 D5
1 0
Figure6.3 Function Command (1 Byte)
D13 D12 D11 D10
0 0 1
Figure6.4 Function Command (2 Bytes)
D4 D3 D2 D1 D0
0 0 Size of data
D9 D8 D7 D6
Size of data
44
Power Supply Controller
(3) Register address (2 bytes)
D5 D4 D3 D2 D1 D0