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R01UH0336EJ0102 Rev.1.02
Page 1119 of 1538
Jul 17, 2014
V850E2/PG4-L
Section 20 CAN Controller (FCN)
• If the CAN bus state is not bus idle (i.e., the CAN bus state is either
transmitting or receiving) when a transition to FCN sleep mode is requested
from one of operating modes, immediate transition to FCN sleep mode is
not possible. In this case, FCN sleep mode transition request is held
pending until the CAN bus state becomes bus idle (the fourth bit in the inter-
frame space is recessive). During the time period from the FCN sleep mode
request to successful transition, FCNnCMCLCTL.FCNnCMCLMDPF[1:0]
remain 00
B
. When the module has entered FCN sleep mode, the
FCNnCMCLMDPF[1:0] bits are set to 01
B
.
• If a request for transition to initialization mode and a request for transition to
FCN sleep mode are made at the same time while the FCN module is in one
of operating modes, the request for initialization mode is enabled. The FCN
module enters initialization mode at a predetermined timing. At this time, the
FCN sleep mode request is not held pending and is ignored.
• Even when initialization mode and sleep mode are not requested
simultaneously (i.e the first request has not been granted while the second
request is made), the request for transition to initialization mode has priority
over the sleep mode request. The sleep mode request is cancelled when
the transition to initialization mode is requested. While a request for
transition to initialization mode is pending, a subsequent request for sleep
mode request is cancelled right at the point in time where it was issued.
(2)
FCN Sleep Mode Status
The FCN module is in the following state after it enters FCN sleep mode.
• The internal operating clock stops and the power consumption is minimized.
• The function to detect the falling edge of the FCN reception pin (FCNnRX)
remains in effect to wake up the FCN module from the CAN bus.
• To wake up the FCN module from the CPU, data can be set for
FCNnCMCLCTL.FCNnCMCLMDPF[1:0], but nothing can be written to other
FCN module registers or bits.
• FCN module registers can be read, except for the FCNnCMLISTR,
FCNnCMRGRX, FCNnCMLOSTR, and FCNnCMTGTX registers.
• FCN message buffer registers cannot be written or read.
• FCNnGMCLCTL.FCNnGMCLSSMO is cleared.
• FCNnDNBMRX registers cannot be read.
• A request for transition to initialization mode is not acknowledged and is
ignored.
Содержание V850 Series
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