SILABS C8051F568-IMR This note already existed in the data sheet in the reset sources chapter, and itâ s been added to additional locations to make it more prominent. Datasheet

Bulletin #1409081
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Bulletin Date: 9/8/2014
Bulletin Effective Date: 9/8/2014
Title: C8051F55x_C8051F56x_C8051F57x_Rev1.2_Data_Sheet_Product_Change_Notice
Originator: Greg Hodgson
Phone: 512-523-5766
Dept: Marketing
Customer Contact: Kathy Haggar
Phone: 512-532-5261
Dept: Sales
Bulletin Details
Description:
Silicon Labs is pleased to announce that version 1.2 of the C8051F55x/56x/57x data sheet is now
available. The revision includes:
Power-On Reset may fail for devices shipped prior to date code 1124
- Added a note regarding an issue with /RST low time on some older devices to “Power-On Reset” on
page 140.
This issue was previously documented in the errata and has now been moved to the data sheet. It has
been removed from the errata.
Note: For devices with a date code before year 2011, work week 24 (1124), if the /RST pin is held low
for more than 1 second while power is applied to the device, and then /RST is released, a percentage
of devices may lock up and fail to execute code. Toggling the /RST pin does not clear the condition.
The condition is cleared by cycling power. Most devices that are affected will show the lock up
behavior only within a narrow range of temperatures (a 5 to 10 degrees C window). Parts with a date
code of year 2011, work week 24 (1124) or later do not have any restrictions on /RST low time. The
date code of a device is a four-digit number on the bottom-most line of each device with the format
YYWW, where YY is the two-digit calendar year and WW is the two digit work week.
Use VDD Monitor low threshold setting during normal operation
– Added the note regarding the voltage regulator and VDD monitor in the high setting from “Power-Fail
Reset/VDD Monitor” on page 140 to “Voltage Regulator (REG0)” on page 80 and “VDD Maintenance and
the VDD monitor” on page 130.
This note already existed in the data sheet in the Reset Sources chapter, and it’s been added to
additional locations to make it more prominent.
Note: The output of the internal voltage regulator is calibrated by the MCU immediately after any
reset event. The output of the un-calibrated internal regulator could be below the high threshold
setting of the VDD Monitor. If this is the case and the VDD Monitor is set to the high threshold setting
and if the MCU receives a non-power on reset (POR), the MCU will remain in reset until a POR occurs
(i.e., VDD Monitor will keep the device in reset). A POR will force the VDD Monitor to the low threshold
setting which is guaranteed to be below the un-calibrated output of the internal regulator. The device
will then exit reset and resume normal operation. It is for this reason Silicon Labs strongly
recommends that the VDD Monitor is always left in the low threshold setting (i.e. default value upon
POR).
W7206F2 Silicon Labs Bulletin rev I
The information contained in this document is PROPRIETARY to Silicon Laboratories, Inc. and shall not be reproduced or used in
part or whole without Silicon Laboratories’ written consent. The document is uncontrolled if printed or electronically saved. Pg 3
Bulletin #1409081
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Use VDD Monitor high setting only when writing Flash
– Updated step 4 in “VDD Maintenance and the VDD monitor” on page 130 to mention using the VDD
monitor in the high setting during flash write/erase operations.
This step previously mentioned using the VDD monitor, but did not specify that the VDD monitor must
be in the high setting in order to write to flash.
Note: When programming the Flash in-system, the VDD Monitor must be set to the high threshold
setting. For the highest system reliability, the time the VDD Monitor is set to the high threshold setting
should be
minimized (e.g., setting the VDD Monitor to the high threshold setting just before the Flash write
operation
and then changing it back to the low threshold setting immediately after the Flash write operation).
Set ZTCEN before entering oscillator suspend
– Updated the SUSPEND bit description in OSCICN (SFR Definition 18.2) to mention that firmware must
set the ZTCEN bit in REF0CN (SFR Definition 7.1) before entering suspend.
This information was already present as a note in section 15.3 Suspend Mode, and it’s been added to
the bit description to make it more prominent.
ZTCEN Zero Temperature Coefficient Bias Enable
Bit.
This bit must be set to 1b before entering
oscillator suspend mode.
IFRDY flag does not accurately reflect the state of the oscillator
– Added a note to the IFRDY flag in the OSCICN register (SFR Definition 18.2) that the flag may not
accurately reflect the state of the oscillator.
IFRDY Internal Oscillator Frequency Ready Flag.
Note: This flag may not accurately reflect the state of the oscillator. Firmware should not use this
flag to determine if the oscillator is running.
VREGIN ramp time max 1 ms for power on specification
– Added VREGIN Ramp Time max 1 ms for Power On spec to Table 5.4, “Reset Electrical
Characteristics,” on page 41.
– Updated “VDD Maintenance and the VDD monitor” on page 130 to refer to 1 ms VREGIN ramp time
instead of 1 ms VDD ramp time.
This specification was previously mentioned in the Flash Write and Erase Guidelines section. It is now
added to the electrical specifications to make it more prominent.
Limited cold programming temperature range for industrial grade (-I) devices
W7206F2 Silicon Labs Bulletin rev I
The information contained in this document is PROPRIETARY to Silicon Laboratories, Inc. and shall not be reproduced or used in
part or whole without Silicon Laboratories’ written consent. The document is uncontrolled if printed or electronically saved. Pg 4
Bulletin #1409081
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– Added a note regarding programming at cold temperatures on –I devices to “Programming The Flash
Memory” on page 125 and added Temperature during Programming Operations specification to Table
5.5, “Flash Electrical Characteristics,” on page 41.
This specification was previously documented in the errata and has now been moved to the data sheet.
It has been removed from the errata.
For –I (Industrial Grade) parts, parts programmed at a cold temperature below 0 °C may exhibit weakly
programmed flash memory bits. If programmed at 0 °C or higher, there is no problem reading Flash
across the entire temperature range of -40 °C to 125 °C. This temperature restriction does not apply
to –A (Automotive Grade) devices.
VREF pin cannot operate as open-drain when VDD selected as reference source
– Added a note regarding P0.0/VREF when VDD is used as the reference to Table 19.1, “Port I/O
Assignment for Analog Functions,” on page 172 and to the description of the REFSL bit in REF0CN (SFR
Definition 7.1).
This issue was previously documented in the errata and has now been moved to the data sheet. It has
been removed from the errata.
If VDD is selected as the voltage reference in the REF0CN register and the ADC is enabled in the
ADC0CN register, the P0.0/VREF pin cannot operate as a general purpose I/O pin in open-drain
mode. With the above settings, this pin can operate in push-pull output mode or as an analog input.
GPIO may have indeterminate state for fast VIO ramp
– Added a note regarding a potential unknown state on GPIO during power up if VIO ramps significantly
before VDD to “Port Input/Output” on page 170 and “Reset Sources” on page 139.
Note: When VIO rises faster than VDD, which can happen when VREGIN and VIO are tied together, a
delay created between GPIO power (VIO) and the logic controlling GPIO (VDD) results in a temporary
unknown state at the GPIO pins. When VIO rises faster than VDD, the GPIO may enter the following
states: floating, glitch low, or glitch high. Cross coupling VIO and VDD with a 4.7 μF capacitor
mitigates the root cause of the problem by allowing VIO and VDD to rise at the same rate.
Set FLEWT bit before writing or erasing flash
– Added steps to set the FLEWT bit in the FLSCL register (SFR Definition 14.3) in the flash write/erase
procedures in “Flash Erase Procedure” on page 126, “Flash Write Procedure” on page 126, and “Flash
Write Optimization” on page 127.
This requirement was previously documented in the bit description for the FLEWT bit, and it’s been
added to the procedures to make it more prominent.
FLEWT Flash Erase Write Time Control.
This bit should be set to 1b before Writing or Erasing Flash.
0: Short Flash Erase / Write Timing.
1: Extended Flash Erase / Write Timing.
VDD monitor may trigger on fast VDD changes
W7206F2 Silicon Labs Bulletin rev I
The information contained in this document is PROPRIETARY to Silicon Laboratories, Inc. and shall not be reproduced or used in
part or whole without Silicon Laboratories’ written consent. The document is uncontrolled if printed or electronically saved. Pg 5
Bulletin #1409081
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– Added a note regarding fast changes on VDD causing the VDD Monitor to trigger to “Power-Fail
Reset/VDD Monitor” on page 140.
Note: The VDD Monitor may trigger on fast changes in voltage on the VDD pin, regardless of whether
the voltage increased or decreased.
UART TX THRE0 bit may return incorrect status
– Added notes regarding UART TX and RX behavior in “Data Transmission” on page 239, “Data
Reception” on page 239, and the THRE0 description in the SCON0 register (SFR Definition 23.1).
Note: THRE0 can have a momentary glitch high when the UART Transmit Holding Register is not empty.
The glitch will occur sometime after SBUF0 was written with the previous byte and does not occur if
THRE0 is checked in the instruction(s) immediately following the write to SBUF0. When firmware
writes SBUF0 and SBUF0 is not empty, TX0 will be stuck low until the next device reset. Firmware
should use or poll on TI0 rather than THRE0 for asynchronous UART writes that may have a random
delay in between transactions.
UART RX may overrun on simultaneous FIFO read/write
– Added notes regarding UART TX and RX behavior in “Data Transmission” on page 239, “Data
Reception” on page 239, and the THRE0 description in the SCON0 register (SFR Definition 23.1).
Note: The UART Receive FIFO pointer can be corrupted if the UART receives a byte and firmware reads
a byte from the FIFO at the same time. When this occurs, firmware will lose the received byte and the
FIFO receive overrun flag (OVR0) will also be set to 1. Systems using the UART Receive FIFO should
ensure that the FIFO isn’t accessed by hardware and firmware at the same time. In other words,
firmware should ensure to read the FIFO before the next byte is received.
Reason:
Clarification of device behavior and inclusion of data sheet version 1.1 errata.
Product Identification:
C8051F550-IM
C8051F551-IM
C8051F552-IM
C8051F553-IM
C8051F554-IM
C8051F555-IM
C8051F556-IM
C8051F557-IM
C8051F560-IM
C8051F560-IQ
C8051F561-IM
C8051F561-IQ
C8051F562-IM
C8051F562-IQ
C8051F563-IM
C8051F563-IQ
C8051F564-IM
C8051F564-IQ
C8051F565-IM
C8051F550-IMR
C8051F551-IMR
C8051F552-IMR
C8051F553-IMR
C8051F554-IMR
C8051F555-IMR
C8051F556-IMR
C8051F557-IMR
C8051F560-IMR
C8051F560-IQR
C8051F561-IMR
C8051F561-IQR
C8051F562-IMR
C8051F562-IQR
C8051F563-IMR
C8051F563-IQR
C8051F564-IMR
C8051F564-IQR
C8051F565-IMR
W7206F2 Silicon Labs Bulletin rev I
The information contained in this document is PROPRIETARY to Silicon Laboratories, Inc. and shall not be reproduced or used in
part or whole without Silicon Laboratories’ written consent. The document is uncontrolled if printed or electronically saved. Pg 6
Bulletin #1409081
_____________________________________________________________________________________________________
C8051F565-IQ
C8051F566-IM
C8051F566-IQ
C8051F567-IM
C8051F567-IQ
C8051F568-IM
C8051F569-IM
C8051F570-IM
C8051F571-IM
C8051F572-IM
C8051F573-IM
C8051F574-IM
C8051F575-IM
C8051F550-AM
C8051F551-AM
C8051F552-AM
C8051F553-AM
C8051F554-AM
C8051F555-AM
C8051F556-AM
C8051F557-AM
C8051F560-AM
C8051F560-IQ
C8051F561-AM
C8051F561-IQ
C8051F562-AM
C8051F562-IQ
C8051F563-AM
C8051F563-IQ
C8051F564-AM
C8051F564-IQ
C8051F565-AM
C8051F565-IQ
C8051F566-AM
C8051F566-IQ
C8051F567-AM
C8051F567-IQ
C8051F568-AM
C8051F569-AM
C8051F570-AM
C8051F571-AM
C8051F572-AM
C8051F573-AM
C8051F574-AM
C8051F575-AM
C8051F565-IQR
C8051F566-IMR
C8051F566-IQR
C8051F567-IMR
C8051F567-IQR
C8051F568-IMR
C8051F569-IMR
C8051F570-IMR
C8051F571-IMR
C8051F572-IMR
C8051F573-IMR
C8051F574-IMR
C8051F575-IMR
C8051F550-AMR
C8051F551-AMR
C8051F552-AMR
C8051F553-AMR
C8051F554-AMR
C8051F555-AMR
C8051F556-AMR
C8051F557-AMR
C8051F560-AMR
C8051F560-IQR
C8051F561-AMR
C8051F561-IQR
C8051F562-AMR
C8051F562-IQR
C8051F563-AMR
C8051F563-IQR
C8051F564-AMR
C8051F564-IQR
C8051F565-AMR
C8051F565-IQR
C8051F566-AMR
C8051F566-IQR
C8051F567-AMR
C8051F567-IQR
C8051F568-AMR
C8051F569-AMR
C8051F570-AMR
C8051F571-AMR
C8051F572-AMR
C8051F573-AMR
C8051F574-AMR
C8051F575-AMR
This change is considered a minor change which does not affect form, fit, function, quality, or
reliability. The information is being provided as a customer courtesy.
Please contact your local Silicon Labs sales representative with any questions about this notification.
A list of Silicon Labs sales representatives may be found at www.silabs.com
Customer Actions Needed:
Review latest revision of the data sheet.
W7206F2 Silicon Labs Bulletin rev I
The information contained in this document is PROPRIETARY to Silicon Laboratories, Inc. and shall not be reproduced or used in
part or whole without Silicon Laboratories’ written consent. The document is uncontrolled if printed or electronically saved. Pg 7
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