Read Microcontroller ATMEGA162A Firmware out and copy this file to other blank MCU ATmega162A in the format of heximal, MCU content recovery process can help engineer to reproduce the heximal file from original Microcontroller;
The UCPOLn bit UCRSC selects which XCKn clock edge is used for data sampling and which is used for data change. As Figure 85 shows, when UCPOLn is zero the data will be changed at rising XCKn edge and sampled at falling XCKn edge.
If UCPOLn is set, the data will be changed at falling XCKn edge and sampled at rising XCKn edge. A serial frame is defined to be one character of data bits with synchronization bits (start and stop bits), and optionally a parity bit for error checking. The USART accepts all 30 combinations of the following as valid frame formats if Microcontroller attiny25 flash reading:
1 start bit
5, 6, 7, 8, or 9 data bits
no, even or odd parity bit
1 or 2 stop bits
A frame starts with the start bit followed by the least significant data bit. Then the next data bits, up to a total of nine, are succeeding, ending with the most significant bit. If enabled, the parity bit is inserted after the data bits, before the stop bits.
When a complete frame is transmitted, it can be directly followed by a new frame, or the communication line can be set to an idle (high) state. Figure 86 illustrates the possible combinations of the frame formats. Bits inside brackets are optional after MCU ATtiny45v program reading.
The frame format used by the USART is set by the UCSZn2:0, UPMn1:0 and USBSn bits in UCSRnB and UCSRnC. The Receiver and Transmitter use the same setting. Note that changing the setting of any of these bits will corrupt all ongoing communication for both the Receiver and Transmitter.
The USART Character SiZe (UCSZn2:0) bits select the number of data bits in the frame. The USART Parity mode (UPMn1:0) bits enable and set the type of parity bit. The selection between one or two stop bits is done by the USART Stop Bit Select (USBSn) bit.
The Receiver ignores the second stop bit. An FE (Frame Error) will therefore only be detected in the cases where the first stop bit is zero.
The parity bit is calculated by doing an exclusive-or of all the data bits. If odd parity is used, the result of the exclusive or is inverted. The relation between the parity bit and data bits. If used, the parity bit is located between the last data bit and first stop bit of a serial frame.
