APPLICATION NOTE Migration Guide from ATA6613C to ATA6614Q ATAN0081 Features ● Atmel® ATA6612C ● Atmel ATA6613C ● Atmel ATA6614Q Description This document outlines important considerations when migrating from the Atmel ATA6612C/ATA6613C to the Atmel ATA6614Q regarding the SBC and microcontroller part. For detailed information on the devices, please refer to the corresponding datasheets. The Atmel ATA6614Q is designed to be pin- and function-compatible with the Atmel ATA6612C/ATA6613C, but because of improvements mentioned in this application note there may be a need for minor software modifications in the application when migrating from Atmel ATA6612C/ATA6613C to the Atmel ATA6614Q. No hardware modifications are necessary. 9320B-AUTO-02/15 1. General Information This application note summarizes the relevant differences when migrating from Atmel® ATA6612C/ATA6613C to Atmel ATA6614Q. For detailed information on the devices, please see the corresponding datasheets. 2. General Porting Considerations for the Microcontroller To make the porting process as easy as possible, we recommend that you always refer to the registers and bit positions using their defined names, because absolute addresses and values may vary from device to device. When porting a design, it is often enough to simply include the correct definition file. Some examples are shown below. Examples of register/bit names PORTE |= (1 << PORTE5); /* Set pin 5 on port E high */ DDRE &= ~(1 << PORT5); /* Set pin 5 on port E as an input */ /* Configure USI */ USICR = ((1 << USISIE) | (1 << USIOIE)); To avoid conflicts with added features and register functionality, never access registers that are marked as reserved. Reserved bits should always be written to “0” if accessed. This ensures forward compatibility, and added features will stay in their default states when unused. 2.1 Register and Bit Names Some register bits have been added in development work between the Atmel ATA6612C/ATA6613C and the Atmel ATA6614Q, but none of the existing bits have been removed or moved to different locations. 2.2 Memory Size The Atmel ATmega328P, which is included in the Atmel ATA6614Q, has twice as much Flash program memory, EEPROM, and internal SRAM respectively, compared to the Atmel ATmega168, which is included in the Atmel ATA6613C. For a comparison of the devices, see Table 2-1. Table 2-1. Comparison of Memory Sizes Flash [bytes] 2.3 Atmel ATA6612C Atmel ATA6613C Atmel ATA6614Q 8192 16384 32768 EEPROM [bytes] 512 512 1024 SRAM [bytes] 1024 1024 2048 Interrupt Vectors The interrupt vectors in the Atmel ATmega88, Atmel ATmega168, and Atmel ATmega328p are generally the same except that each interrupt vector occupies two instruction words in the Atmel ATmega168 and the Atmel ATmega328p and one instruction word in the Atmel ATmega88. 2 ATAN0081 [APPLICATION NOTE] 9320B–AUTO–02/15 2.4 Low-frequency Crystal/Timer/Counter Oscillator The low-frequency crystal oscillator of the Atmel® ATA6614Q is optimized for very low power consumption so that the crystal driver strength is reduced compared to the Atmel ATA6612C/ATA6613C. This means that when selecting a crystal, its load capacitance and equivalent series resistance (ESR) must be taken into consideration. Both values are specified by the crystal vendor. The internal capacitance of the ATA6614Q low-frequency oscillator is typically 6pF, but the tracks to the crystal will add some additional capacitance. Table 2-2 shows the ESR recommendations for the Atmel ATA6614Q. Table 2-2. Note: 1. ESR Recommendation for 32.768kHz Crystals for the Atmel ATA6614Q Crystal CL [pF] Max ESR(1)[kΩ] 6.5 75 9 65 12.5 30 The values stated are for an oscillator allowance safety margin of 5. Because the oscillator’s transconductance is temperature compensated, a safety margin of 4 can be used, resulting in a maximum ESR of 90k, 80k, and 40k respectively. The start-up times are increased as shown in Table 2-3. Table 2-3. Start-up Times with 32.768kHz Crystals Crystal CL [pF] Start-up Time(2) [ms] ATA6612C/13C Start-up Time(2) [ms] ATA6614Q 6.5 - 600 9 300 700 12.5 400 1700 Note: 1. Crystals usually require ~3000ms before they are completely stable with any oscillator design. The time stated is before the crystal is running with a sufficient amplitude and frequency stability. Only the low-frequency oscillator is affected by this change. There are no special considerations for the other oscillators included. ATAN0081 [APPLICATION NOTE] 9320B–AUTO–02/15 3 3. Differences between the SBCs The current consumption of the Atmel® ATA6630 has been improved compared to the Atmel ATA6624C, resulting in lower current consumption for the Atmel ATA6614Q compared to the Atmel ATA6612C and the Atmel ATA6613C. For more information, see the datasheets. 3.1 ESD According to IBEE LIN EMC Test Spec. 1.0 Based on IEC 61000-4-2 Heading 2 The Atmel ATA6630 (Atmel ATA6614Q) has improved ESD immunity compared to the Atmel ATA6624 (Atmel ATA6612C/ATA6613C) for this test. It is rated for ±8kV min. while the Atmel ATA6612C and the Atmel ATA6613C are rated for a minimum of ±6kV. 3.2 Wake-up Source Recognition The Atmel ATA6630 uses a different way to indicate the wake-up source. The software has to be adjusted to use the changed/new signals. Table 3-1. Fail-safe Source TXD RXD LIN wake-up (pin LIN) High Low Local wake-up (at pin WAKE, pin KL_15) Low Low Table 3-2. Fail-safe Source Indication for the Atmel ATA6614Q Fail-safe Source TXD RXD LIN wake-up (pin LIN) Low Low Local wake-up (at pin WAKE, pin KL_15) Low High VSth (battery) undervoltage detection High Low Table 3-3. 3.3 Fail-safe Source Indication for the Atmel ATA6612C/ATA6613C Fail-safe Mode Indication after a Reset (NRES was Low) Shows the Reset Source at TXD and RXD Pins for the Atmel ATA6614Q Fail-safe Source TXD RXD VCC undervoltage High Low Watchdog reset High High TXD Time-out Timer The timings for the TXD dominant time-out timer have changed. To allow lower bit rates, the minimum time at which a timeout is detected has been increased. Table 3-4 shows the exact timings for the devices. Table 3-4. 4 TXD Time-out Time Type Min Typical Max ATA6612C/ATA6613C (ATA6624) 6ms 13ms 20ms ATA6614Q (ATA6630) 27ms 55ms 70ms ATAN0081 [APPLICATION NOTE] 9320B–AUTO–02/15 XXXXXX Atmel Corporation 1600 Technology Drive, San Jose, CA 95110 USA T: (+1)(408) 441.0311 F: (+1)(408) 436.4200 | www.atmel.com © 2015 Atmel Corporation. / Rev.: 9320B–AUTO–02/15 Atmel®, Atmel logo and combinations thereof, Enabling Unlimited Possibilities®, and others are registered trademarks or trademarks of Atmel Corporation in U.S. and other countries. Other terms and product names may be trademarks of others. DISCLAIMER: The information in this document is provided in connection with Atmel products. No license, express or implied, by estoppel or otherwise, to any intellectual property right is granted by this document or in connection with the sale of Atmel products. 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