Datasheet

V850ES/JG3 CHAPTER 16 3-WIRE VARIABLE-LENGTH SERIAL I/O (CSIB)
R01UH0015EJ0300 Rev.3.00 Page 494 of 870
Sep 30, 2010
(4) CSIBn status register (CBnSTR)
CBnSTR is an 8-bit register that displays the CSIBn status.
This register can be read or written in 8-bit or 1-bit units, but the CBnTSF flag is read-only.
Reset sets this register to 00H.
In addition to reset input, the CBnSTR register can be initialized by clearing (0) the CBnCTL0.CBnPWR bit.
CBnTSF
Communication stopped
Communicating
CBnTSF
0
1
Communication status flag
CBnSTR
(n = 0 to 4)
00 0 00 0 CBnOVE
After reset 00H R/W Address: CB0STR FFFFFD03H, CB1STR FFFFFD13H,
CB2STR FFFFFD23H, CB3STR FFFFFD33H,
CB4STR FFFFFD43H
• During transmission, this register is set when data is prepared in the CBnTX
register, and during reception, it is set when a dummy read of the CBnRX register
is performed.
When transfer ends, this flag is cleared to 0 at the last edge of the clock.
No overrun
Overrun
CBnOVE
0
1
Overrun error flag
• An overrun error occurs when the next reception completes without reading the
value of the receive buffer by CPU, upon completion of the receive operation.
The CBnOVE flag displays the overrun error occurrence status in this case.
• The CBnOVE bit is valid also in the single transfer mode. Therefore, when only
using transmission, note the following.
• Do not check the CBnOVE flag.
• Read this bit even if reading the reception data is not required.
•
The CBnOVE flag is cleared by writing 0 to it. It cannot be set even by writing 1 to it.
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