
72
4680C–4BMCU–01/05
ATAM893-D
5.3.4.15
Serial Transmit Buffer (STB) – Byte Write
The STB is the transmit buffer of the SSI. The SSI transfers the transmit buffer into the shift register and
starts shifting with the most significant bit.
5.3.4.16
Serial Receive Buffer (SRB) – Byte Read
The SRB is the receive buffer of the SSI. The shift register clocks serial data in (most significant bit first)
and the loads content into the receive buffer when the complete telegram has been received.
5.3.5
Combination Modes
The UTCM consists of two timers (Timer 2 and Timer 3) and a serial interface. There is a multi-
tude of modes in which the timers and serial interface can work together.
The 8-bit wide serial interface operates as shift register for modulation and demodulation. The
modulator and demodulator units work together with the timers and shift the data bits into or out
of the shift register.
Primary register address: '9'hex
First write cycle
Bit 3
Bit 2
Bit 1
Bit 0
Reset value: xxxxb
Second write cycle
Bit 7
Bit 6
Bit 5
Bit 4
Reset value: xxxxb
Primary register address: '9'hex
First read cycle
Bit 7
Bit 6
Bit 5
Bit 4
Reset value: xxxxb
Second read cycle
Bit 3
Bit 2
Bit 1
Bit 0
Reset value: xxxxb