DM8603EP DAVICOM [Davicom Semiconductor, Inc.], DM8603EP Datasheet - Page 70

• Manufacturer Part Number: DM8603EP
• Description: 10/100 Mbps 3-port Ethernet Switch Controller with MII / RMII Interface
• Manufacturer: DAVICOM [Davicom Semiconductor, Inc.]

9.1.2
command validity to suppress the mistaken command. In write procedure, the written value in register will be
applied until the correct checksum is written (error proofing) and user can read status for validation (error
detecting). In read procedure, user can compare hardware calculated checksum with software calculated
one to validate the result.
For example:
Checksum calculate formula:
Note:
Preliminary datasheet
DM8603-12-DS-P01
November 8, 2010
Because SMI bus tends to be interfered by noise on board-level. This function is used to check the
CSUM[0]
CSUM[1]
CSUM[2]
CSUM[3]
CSUM[4]
CSUM[5]
CSUM[6]
CSUM[7]
D[15:0]
R[4:0]
A[4:0]
OP[1:0]
Write Procedure
(1). Set REG 19h.1Ah.[0] = 1 to enable SMI Bus Error Check function
(2). Write data to DM8603's register (general write command)
(3). CPU calculate checksum (CSUM[7:0]) and write it to REG 19h.19h.[7:0]
(4). Check function status REG 19h.19h.[8]
Read Procedure
(1). Set REG 19h.1Ah.[0] = 1 to enable SMI Bus Error Check function
(2). Read data from DM8603's register (general read command)
(3). Read hardware calculated checksum from REG 19h.19h.[7:0] and compare it with CPU calculated
Host SMI Bus Error Check Function
one (CSUM[7:0])
= <Data> field of SMI frame
= <Register Address> field of SMI frame
= <PHY Address> field of SMI frame
= <Op Code> field of SMI frame
=
=
=
=
=
=
=
=
D[0]
D[1]
D[2]
D[3]
D[4]
D[5]
D[6]
D[7]
^
^
^
^
^
^
^
^
D[10] ^
D[11] ^
D[12] ^
D[13] ^
D[14] ^
D[15] ^
D[8]
D[9]
^
^
10/100 Mbps 3-port Ethernet Switch Controller with MII / RMII Interface
R[1]
R[2]
R[3]
R[4]
A[0]
A[1]
A[2]
R[0]
^
^
^
^
OP[0]
OP[1]
A[3]
A[4]
DM8603
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