參數(shù)資料
型號(hào): ST72521BM6
英文描述: ST72521B - 80/64-PIN 8-BIT MCU WITH 32 TO 60K ROM. FIVE TIMERS. SPI. SCI. I2C. CAN INTERFACE
中文描述: ST72521B - 80/64-PIN 8位32至60,000 ROM的微處理器。 5個(gè)定時(shí)器。的SPI。脊髓損傷。 I2C總線。 CAN接口
文件頁(yè)數(shù): 129/198頁(yè)
文件大?。?/td> 2504K
代理商: ST72521BM6
第1頁(yè)第2頁(yè)第3頁(yè)第4頁(yè)第5頁(yè)第6頁(yè)第7頁(yè)第8頁(yè)第9頁(yè)第10頁(yè)第11頁(yè)第12頁(yè)第13頁(yè)第14頁(yè)第15頁(yè)第16頁(yè)第17頁(yè)第18頁(yè)第19頁(yè)第20頁(yè)第21頁(yè)第22頁(yè)第23頁(yè)第24頁(yè)第25頁(yè)第26頁(yè)第27頁(yè)第28頁(yè)第29頁(yè)第30頁(yè)第31頁(yè)第32頁(yè)第33頁(yè)第34頁(yè)第35頁(yè)第36頁(yè)第37頁(yè)第38頁(yè)第39頁(yè)第40頁(yè)第41頁(yè)第42頁(yè)第43頁(yè)第44頁(yè)第45頁(yè)第46頁(yè)第47頁(yè)第48頁(yè)第49頁(yè)第50頁(yè)第51頁(yè)第52頁(yè)第53頁(yè)第54頁(yè)第55頁(yè)第56頁(yè)第57頁(yè)第58頁(yè)第59頁(yè)第60頁(yè)第61頁(yè)第62頁(yè)第63頁(yè)第64頁(yè)第65頁(yè)第66頁(yè)第67頁(yè)第68頁(yè)第69頁(yè)第70頁(yè)第71頁(yè)第72頁(yè)第73頁(yè)第74頁(yè)第75頁(yè)第76頁(yè)第77頁(yè)第78頁(yè)第79頁(yè)第80頁(yè)第81頁(yè)第82頁(yè)第83頁(yè)第84頁(yè)第85頁(yè)第86頁(yè)第87頁(yè)第88頁(yè)第89頁(yè)第90頁(yè)第91頁(yè)第92頁(yè)第93頁(yè)第94頁(yè)第95頁(yè)第96頁(yè)第97頁(yè)第98頁(yè)第99頁(yè)第100頁(yè)第101頁(yè)第102頁(yè)第103頁(yè)第104頁(yè)第105頁(yè)第106頁(yè)第107頁(yè)第108頁(yè)第109頁(yè)第110頁(yè)第111頁(yè)第112頁(yè)第113頁(yè)第114頁(yè)第115頁(yè)第116頁(yè)第117頁(yè)第118頁(yè)第119頁(yè)第120頁(yè)第121頁(yè)第122頁(yè)第123頁(yè)第124頁(yè)第125頁(yè)第126頁(yè)第127頁(yè)第128頁(yè)當(dāng)前第129頁(yè)第130頁(yè)第131頁(yè)第132頁(yè)第133頁(yè)第134頁(yè)第135頁(yè)第136頁(yè)第137頁(yè)第138頁(yè)第139頁(yè)第140頁(yè)第141頁(yè)第142頁(yè)第143頁(yè)第144頁(yè)第145頁(yè)第146頁(yè)第147頁(yè)第148頁(yè)第149頁(yè)第150頁(yè)第151頁(yè)第152頁(yè)第153頁(yè)第154頁(yè)第155頁(yè)第156頁(yè)第157頁(yè)第158頁(yè)第159頁(yè)第160頁(yè)第161頁(yè)第162頁(yè)第163頁(yè)第164頁(yè)第165頁(yè)第166頁(yè)第167頁(yè)第168頁(yè)第169頁(yè)第170頁(yè)第171頁(yè)第172頁(yè)第173頁(yè)第174頁(yè)第175頁(yè)第176頁(yè)第177頁(yè)第178頁(yè)第179頁(yè)第180頁(yè)第181頁(yè)第182頁(yè)第183頁(yè)第184頁(yè)第185頁(yè)第186頁(yè)第187頁(yè)第188頁(yè)第189頁(yè)第190頁(yè)第191頁(yè)第192頁(yè)第193頁(yè)第194頁(yè)第195頁(yè)第196頁(yè)第197頁(yè)第198頁(yè)
ST72521B
129/198
CONTROLLER AREA NETWORK
(Cont’d)
RESYNC
. The resynchronization mode is used
to find the correct entry point for starting trans-
mission or reception after the node has gone
asynchronous either by going into the STANDBY
or bus-off states.
Resynchronization is achieved when 128 se-
quences of 11 recessive bits have been moni-
tored unless the node is not bus-off and the
FSYN bit in the CSR register is set in which case
a single sequence of 11 recessive bits needs to
be monitored.
IDLE
. The CAN controller looks for one of the fol-
lowing events: the RUN bit is reset, a Start Of
Frame appears on the CAN bus or the DATA7
register of the currently active page is written to.
TRANSMISSION
. Once the LOCK bit of a Buffer
Control/Status Register (BCSRx) has been set
and read back as such, a transmit job can be
submitted by writing to the DATA7 register. The
message with the highest priority will be transmit-
ted as soon as the CAN bus becomes idle.
Among those messages with a pending trans-
mission request, the highest priority is given to
Buffer 3 then 2 and 1. If the transmission fails due
to a lost arbitration or to an error while the NRTX
bit of the CSR register is reset, then a new trans-
mission attempt is performed . This goes on until
the transmission ends successfully or until the
job is cancelled by unlocking the buffer, by set-
ting the NRTX bit or if the node ever enters bus-
off or if a higher priority message becomes pend-
ing. The RDY bit in the BCSRx register, which
was set since the job was submitted, gets reset.
When a transmission is in progress, the BUSY bit
in the BCSRx register is set. If it ends successful-
ly then the TXIF bit in the Interrupt Status Regis-
ter (ISR) is set, else the TEIF bit is set. An
interrupt is generated in either case provided the
TXIE and TEIE bits of the ICR register are set.
The ETX bit in the same register is used to get an
early transmit interrupt and to automatically un-
lock the transmitting buffer upon successful com-
pletion of its job. This enables the CPU to get a
new transmit job pending by the end of the cur-
rent transmission while always leaving two buff-
ers available for reception. An uninterrupted
stream of messages may be transmitted in this
way at no overrun risk.
Note 1:
Setting the SRTE bit of the CSR register
allows transmitted messages to be simultane-
ously received when they pass the acceptance
filtering. This is particularly useful for checking
the integrity of the communication path.
Note 2:
When the ETX bit is reset, the buffer with
the highest priority and with a pending transmis-
sion request is always transmitted. When the
ETX bit is set, once a buffer participates in the ar-
bitration phase, it is sent until it wins the arbitra-
tion even if another transmission is requested
from a buffer with a higher priority.
RECEPTION
. Once the CAN controller has syn-
chronized itself onto the bus activity, it is ready
for reception of new messages. Every incoming
message gets its identifier compared to the ac-
ceptance filters. If the bitwise comparison of the
selected bits ends up with a match for at least
one of the filters then that message is elected for
reception and a target buffer is searched for. This
buffer will be the first one - order is 1 to 3 - that
has the LOCK and RDY bits of its BCSRx regis-
ter reset.
– When no such buffer exists then an overrun
interrupt is generated if the ORIE bit of the ICR
register has been set. In this case the identifi-
er of the last message is made available in the
Last Identifier Register (LIDHR and LIDLR) at
least until it gets overwritten by a new identifi-
er picked-up from the bus.
– When a buffer does exist, the accepted mes-
sage gets written into it, the ACC bit in the
BCSRx register gets the number of the match-
ing filter, the RDY and RXIF bits get set and an
interrupt is generated if the RXIE bit in the ISR
register is set.
Up to three messages can be automatically
received without intervention from the CPU
because each buffer has its own set of status
bits, greatly reducing the reactiveness require-
ments in the processing of the receive inter-
rupts.
相關(guān)PDF資料
PDF描述
ST72521BM9 ST72521B - 80/64-PIN 8-BIT MCU WITH 32 TO 60K ROM. FIVE TIMERS. SPI. SCI. I2C. CAN INTERFACE
ST72521BR6 ST72521B - 80/64-PIN 8-BIT MCU WITH 32 TO 60K ROM. FIVE TIMERS. SPI. SCI. I2C. CAN INTERFACE
ST72521BR9 ST72521B - 80/64-PIN 8-BIT MCU WITH 32 TO 60K ROM. FIVE TIMERS. SPI. SCI. I2C. CAN INTERFACE
ST78C34 GENERAL PURPOSE PARALLEL PRINTER PORT WITH 83 BYTE FIFO
ST78C34CJ44 GENERAL PURPOSE PARALLEL PRINTER PORT WITH 83 BYTE FIFO
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
ST72561K4 制造商:STMicroelectronics 功能描述:LOW SPEED USB 8-BIT MCU WITH 3 ENDPOINTS,FLASH MEMORY, - Bulk
ST72589-EMU2 功能描述:仿真器/模擬器 ST7 Emulator Board RoHS:否 制造商:Blackhawk 產(chǎn)品:System Trace Emulators 工具用于評(píng)估:C6000, C5000, C2000, OMAP, DAVINCI, SITARA, TMS470, TMS570, ARM 7/9, ARM Cortex A8/R4/M3 用于:XDS560v2
ST72611F1 制造商:STMicroelectronics 功能描述:LOW SPEED USB 8-BIT MCU WITH 3 ENDPOINTS,FLASH MEMORY, - Bulk
ST7263-EMU2 功能描述:仿真器/模擬器 ST7 Emulator Board RoHS:否 制造商:Blackhawk 產(chǎn)品:System Trace Emulators 工具用于評(píng)估:C6000, C5000, C2000, OMAP, DAVINCI, SITARA, TMS470, TMS570, ARM 7/9, ARM Cortex A8/R4/M3 用于:XDS560v2
ST7265X-EVAL/MS 制造商:STMicroelectronics 功能描述:ST6 EVAL BD - Bulk