AT83C51IC2_14 Datasheet, PDF (1/4 Pages) ATMEL Corporation – During UART Reception, Clearing REN May Generate Unexpected IT

Active Errata List
• During UART Reception, Clearing REN May Generate Unexpected IT
• SPI Interface - Transmission on Master Mode
• SPI Interface - SPI SS pin Limitation on Master/Slave
• SPI - SPI Slave Responding in a Multislave Configuration When Not Selected by the
Master and its SPDAT Register Loaded
• SPI - SPI Slave Not Responding When Selected and Not Loaded
• ALE Disabled Toggles During Internal MOVX
• Timer 2 - Baud Rate Generator - No IT When TF2 is Set by Software
• Timer 2 - Baud Rate Generator - Long Start Time
• SPI Slave Mode/Data Corrupted
• 32 kHz Oscillator for AT83C51IC2/T80C51ID2 Needs External Feed Back Resistor
• RB8 Lost With JBC on SCON
• C51 Core – Bad Exit of Power-down in X2 Mode
Errata History
Rev Lot Number 1st Prod. Trouble List
A
above 00395 Nov 2001 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11
Errata Descriptions
1. During UART Reception, Clearing REN May Generate Unexpected IT
During UART reception, if the REN bit is cleared between a start bit detection and
the end of reception, the UART will not discard the data (RI is set).
Workaround
Test REN at the beginning of Interrupt routine just after CLR RI, and run the Inter-
rupt routine code only if REN is set.
2. SPI Interface - Transmission on Master Mode
A 9th bit is transmitted by the interface when the clock rate is set on divide by 2
mode and a positive polarity is selected; the SPR2, SPR1, SPR0 bits are cleared
(000) and CPOL = 1 on the SPCON register.
Workaround
Set the clock rate divide by 4 and X2 mode.
3. SPI Interface - SPI SS pin Limitation on Master/Slave
The SS pin of the SPI does not return to an I/O when a One-to-One Master/Slave
intercommunication is performed.
Workaround
No
4. SPI - SPI Slave Responding in a Multislave Configuration When Not
Selected by the Master and its SPDAT Register Loaded
In a multislave configuration, if the master is sending the Sck and the Tx data to all
the slaves, and only one slave is selected, the non-selected slaves respond and
generate the end of the transmission interruption (SPIF) if their SPDAT registers
are loaded before the transmission.
Workaround
No
80C51 MCUs
AT83C51RB2
AT83C51RC2
AT83C51IC2
AT80C51ID2
AT80C51RD2
Errata Sheet
4242B–8051–03/08