RX5C348A Datasheet, PDF (26/45 Pages) RICOH electronics devices division – 4-WIRE SERIAL INTERFACE

Rx5C348A/B
Good Example
Time span of 31µs or more
CE
Any address other than addresses 0h to 6h
permits of immediate reading or writing without
requiring a time span of 31 µs.
SI
F4h
SO
DATA
DATA
DATA
DATA
Address Pointer
= Fh
Transfer Format
Register = 4h
Reading from
Address Fh
(control2)
Reading from
Address 0h
(sec.)
Reading from
Address 1h
(min.)
Reading from
Address 2h
(hr.)
Bad Example (1)
(Where the CE pin is once driven low in the process of reading time data)
31µs or more
31µs or more
CE
SI
0Ch
14h
SO
Data
Data
Data
Address Pointer
= 0h
Transfer Format
Register = Ch
Reading from
Address 0h
(sec.)
Address Pointer
= 1h
Transfer Format
Register = 4h
Reading from
Address 1h
(min.)
Reading from
Address 2h
(hr.)
Bad Example (2)
(Where a time span of less than 31µs is left until the start of the process of writing time data)
Time span of less than 31µs
CE
SI
F0h
Data
Data
Data
Data
SO
Address Pointer
= Fh
Transfer Format
Register = 0h
Writing to
Address Fh
(contorl2)
Writing to
Address 0h
(sec.)
Writing to
Address 1h
(min.)
Writing to
Address 2h
(hr.)
Bad Example (3)
(Where a time span of less than 61µs is left between the adjacent processes of reading time data)
Less than 62µs
CE
SI
0Ch
SO
Data
Address Pointer
= 0h
Transfer Format
Register = Ch
Reading from
Address 0h
(sec.)
0Ch
Data transfer from the host
Data
0Ch
Address Pointer
= 0h
Transfer Format
Register = Ch
Data
Reading from
Address 0h
(sec.)
Data transfer from RTCs
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