Datasheet

V850ES/JG3-H, V850ES/JH3-H CHAPTER 18 3-WIRE VARIABLE-LENGTH SERIAL I/O (CSIF)
R01UH0042EJ0500 Rev.5.00 Page 775 of 1513
Aug 12, 2011
(4) CSIFn status register (CFnSTR)
CFnSTR is an 8-bit register that displays the CSIFn status.
This register can be read or written in 8-bit or 1-bit units, but the CFnTSF flag is read-only.
Reset sets this register to 00H.
In addition to reset input, the CFnSTR register can be initialized by clearing (0) the CFnCTL0.CFnPWR bit.
CFnTSF
Communication stopped
Communicating
CFnTSF
0
1
Communication status flag
CFnSTR
(n = 0 to 4)
00 0 00 0 CFnOVE
After reset: 00H R/W Address: CF0STR FFFFFD03H, CF1STR FFFFFD13H,
CF2STR FFFFFD23H, CF3STR FFFFFD33H,
CF4STR FFFFFD43H
• During transmission, this register is set when data is prepared in the CFnTX
register, and during reception, it is set when a dummy read of the CFnRX register
is performed.
When transfer ends, this flag is cleared to 0 at the last edge of the clock.
No overrun
Overrun
CFnOVE
0
1
Overrun error flag
• An overrun error occurs when the next reception is completed without the CPU
reading the value of the receive buffer, upon completion of the receive operation.
The CFnOVE flag displays the overrun error occurrence status in this case.
• The CFnOVE bit is valid also in the single transfer mode. Therefore, when only
using transmission, note the following.
• Do not check the CFnOVE flag.
• Read this bit even if reading the reception data is not required.
•
The CFnOVE flag is cleared by writing 0 to it. It cannot be set even by writing 1 to it.
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