![NXP Semiconductors LPC43Sxx Скачать руководство пользователя страница 1263](http://html1.mh-extra.com/html/nxp-semiconductors/lpc43sxx/lpc43sxx_user-manual_17218271263.webp)
UM10503
All information provided in this document is subject to legal disclaimers.
© NXP B.V. 2015. All rights reserved.
User manual
Rev. 2.1 — 10 December 2015
1263 of 1441
NXP Semiconductors
UM10503
Chapter 45: LPC43xx/LPC43Sxx C_CAN
45.6.4 CAN timing register
45.6.4.1 CAN clock divider register
This register determines the CAN clock signal. The CAN_CLK is derived from the
peripheral clock PCLK divided by the values in this register.
45.7 Functional description
45.7.1 C_CAN controller state after reset
After a hardware reset, the registers hold the values described in
. Additionally,
the busoff state is reset and the output CAN_TX is set to recessive (HIGH). The value
0x0001 (INIT = ‘1’) in the CAN Control Register enables the software initialization. The
CAN controller does not communicate with the CAN bus until the CPU resets INIT to ‘0’.
The data stored in the message RAM is not affected by a hardware reset. After power-on,
the contents of the message RAM is undefined.
45.7.2 C_CAN operating modes
45.7.2.1 Software initialization
The software initialization is started by setting the bit INIT in the CAN Control Register,
either by software or by a hardware reset, or by entering the busoff state.
Table 1076.CAN message valid 2 register (MSGV2, address 0x400E 2164 (C_CAN0) and
0x400A 4164 (C_CAN1)) bit description
Bit
Symbol
Description
Access
Reset
value
15:0
MSGVAL32_17
Message valid bits of message objects 32 to 17.
0 = This message object is ignored by the message
handler.
1 = This message object is configured and should
be considered by the message handler.
R
0x00
31:16 -
Reserved
-
-
Table 1077.CAN clock divider register (CLKDIV, address 0x400E 2180 (C_CAN0) and 0x400A
4180 (C_CAN1)) bit description
Bit
Symbol
Description
Reset
value
Access
3:0
CLKDIVVAL Clock divider value
CAN_CLK = PCLK/(CLK1)
0000: CAN_CLK = PCLK divided by 1.
0001: CAN_CLK = PCLK divided by 2.
0010: CAN_CLK = PCLK divided by 3.
0011: CAN_CLK = PCLK divided by 4.
0100: CAN_CLK = PCLK divided by 5.
...
1111: CAN_CLK = PCLK divided by 16.
0001
R/W
31:4
-
reserved
-
-