SAB80C517-M16 SIEMENS [Siemens Semiconductor Group], SAB80C517-M16 Datasheet - Page 92

• Manufacturer Part Number: SAB80C517-M16
• Description: 8-Bit CMOS Single-Chip Microcontroller
• Manufacturer: SIEMENS [Siemens Semiconductor Group]

7.5
The compare/capture unit is one of the SAB 80C517’s most powerful peripheral units for use in all
kinds of digital signal generation and event capturing like pulse generation, pulse width modulation,
pulse width measuring etc.
The CCU consists of two 16-bit timer/counters with automatic reload feature and an array of 13
compare or compare/capture registers. A set of six control registers is used for flexible adapting of
the CCU to a wide variety of user’s applications.
The CCU is the ideal peripheral for various automotive control applications (ignition/injection
control, anti-lock brakes, etc.) as well as for industrial applications (DC, three-phase AC, and
stepper motor control, frequency generation, digital-to-analog conversion, process control, etc.)
The detailed description in the following sections refers to the CCU’s functional blocks as listed
below:
Altogether the register array may control up to 21 output lines and can request up to 7 independent
interrupts.
For brevity, in the following text all double-byte compare, compare/capture or compare/reload/
capture registers are called CMx (x = 0 … 7), CCx (x = 0 … 4) or CRC register, respectively.
The block diagram in figure 7-33 shows the general configuration of the CCU. All CCx registers and
the CRC register are exclusively assigned to timer 2. Each of the eight compare registers CM0
through CM7 can either be assigned to timer 2 or to the faster compare timer, e.g. to provide up to
8 PWM channels. The assignment of the CMx registers - which can be done individually for every
single register - is combined with an automatic selection of one of the two possible compare modes.
Semiconductor Group
– Timer 2 with
– Compare timer with
– Compare/(reload/)capture register array consisting of four different kinds of registers:
mark "BB" or later), 16-bit reload, counter/gated timer mode and overflow interrupt request.
request.
one 16-bit compare/reload/capture register,
three 16-bit compare/capture registers,
one 16-bit compare/capture register with additional "concurrent compare" feature,
eight 16-bit compare registers with timer-overflow controlled loading.
The Compare/Capture Unit (CCU)
f
OSC
/12 input clock, 2-bit prescaler, (4-bit prescaler, in SAB 80C517 identification
f
OSC
/2 input clock, 8-bit prescaler, 16-bit reload and overflow interrupt
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On-Chip Peripheral Components