T89C51CC01UA-RLTIM Atmel, T89C51CC01UA-RLTIM Datasheet - Page 6

• Manufacturer Part Number: T89C51CC01UA-RLTIM
• Description: IC 8051 MCU FLASH 32K 44VQFP
• Manufacturer: Atmel
• Series: AT89C CANr

Specifications of T89C51CC01UA-RLTIM

• Core Processor: 8051
• Core Size: 8-Bit
• Speed: 40MHz
• Connectivity: CAN, UART/USART
• Peripherals: POR, PWM, WDT
• Number Of I /o: 32
• Program Memory Size: 32KB (32K x 8)
• Program Memory Type: FLASH
• Eeprom Size: 2K x 8
• Ram Size: 1.25K x 8
• Voltage - Supply (vcc/vdd): 3 V ~ 5.5 V
• Data Converters: A/D 8x10b
• Oscillator Type: External
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 44-TQFP, 44-VQFP
• For Use With: AT89STK-06 - KIT DEMOBOARD 8051 MCU W/CAN
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Other names: T89C51CC01UARLTIM

6
Workaround
Workaround implementation
T89C51CC01 Errata Sheet
1. At least one Receive MOB of the chip are programmed to accept the incoming message. In
this case, the transmitter will wait for the next 3-bit Intermission to retry its transmission.
2. No Receive MOB of the chip are programmed to accept the incoming message. In this case
the transmitter will wait for a 4-bit Intermission to retry its transmission. In this case, any other
CAN nodes ready to transmit after a 3-bit Intermission will start transmit before the chip transmit-
ter, even if their messages have lower priority IDs.
Always have a Receive MOB enabled ready to accept any incoming messages. Thanks to the
implementation of the CAN interface, a Receive MOB must be enable at latest, before the 1
of the DLC field. The Receive MOB status register is written (RXOK if message OK) immediately
after the 6th bit of the End of Frame field. This will leave in CAN2.0A mode a minimum 19-bit
time delay to respond to the end of message interrupt (RXOK) and re-enable the Receive MOB
before the start of the DLC field of the next incoming message. This minimum delay will be 39-bit
time in CAN2.0B. See CAN2.0A CAN2.0B frame timings below.
The workaround is to have the last MOb (MOb14) as "spy" enabled all the time; it is the MOb of
lowest priority : If a Mob other than MOb14 is programmed in receive mode and its acceptance
filter matches with the incoming message ID, this Mob will take the message. MOb14 will only
take messages than no other MObs will have accepted. MOb14 will need to be re-enabled fast
enough to manage back to back frames. The deadline to do this is the beginning of DLC slot of
incoming frames as explained above.
CAN2.0A
CAN2.0B
T 1
T 1
T 1
T 1
T 1
T 1
19 bit time minimum
39 bit time minimum
T 2
T 2
T 2
4131J–CAN–05/06
T 2
T 2
T 2
st
bit