SAF-C161U-LF V1.3 Infineon Technologies, SAF-C161U-LF V1.3 Datasheet - Page 194

• Manufacturer Part Number: SAF-C161U-LF V1.3
• Description: IC MCU ISDN 16BIT TTL TQFP-100
• Manufacturer: Infineon Technologies
• Series: C16xxr

Specifications of SAF-C161U-LF V1.3

• Core Processor: C166
• Core Size: 16-Bit
• Speed: 36MHz
• Connectivity: EBI/EMI, SPI, UART/USART, USB
• Peripherals: POR, PWM, WDT
• Number Of I /o: 56
• Program Memory Type: ROMless
• Ram Size: 3K x 8
• Voltage - Supply (vcc/vdd): 3 V ~ 3.6 V
• Oscillator Type: External
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 100-LFQFP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -
• Program Memory Size: -
• Data Converters: -
• Other names: SAFC161ULFV1.3X; SAFC161ULFV13XP; SP000007502

Data Sheet
Synchronous READY provides the fastest bus cycles, but requires setup and hold
times to be met. The CLKOUT signal should be enabled and may be used by the
peripheral logic to control the READY timing in this case.
Asynchronous READY is less restrictive, but requires additional waitstates caused by
the internal synchronization. As the asynchronous READY is sampled earlier (see figure
above) programmed waitstates may be necessary to provide proper bus cycles (see also
notes on “normally-ready” peripherals below).
A READY signal (especially asynchronous READY) that has been activated by an
external device may be deactivated in response to the trailing (rising) edge of the
respective command (RD or WR).
Note: When the READY function is enabled for a specific address window, each bus
Combining the READY function with predefined waitstates is advantageous in two
cases:
Memory components with a fixed access time and peripherals operating with READY
may be grouped into the same address window. The (external) waitstate control logic in
this case would activate READY either upon the memory’s chip select or with the
peripheral’s READY output. After the predefined number of waitstates the C161U will
check its READY line to determine the end of the bus cycle. For a memory access it will
be low already (see example a) in the figure above), for a peripheral access it may be
delayed (see example b) in the figure above). As memories tend to be faster than
peripherals, there should be no impact on system performance.
When using the READY function with so-called “normally-ready” peripherals, it may lead
to erroneous bus cycles, if the READY line is sampled too early. These peripherals pull
their READY output low, while they are idle. When they are accessed, they deactivate
READY until the bus cycle is complete, then drive it low again. If, however, the peripheral
deactivates READY after the first sample point of the C161U, the controller samples an
active READY and terminates the current bus cycle, which, of course, is too early. By
inserting predefined waitstates the first READY sample point can be shifted to a time,
where the peripheral has safely controlled the READY line (eg. after 2 waitstates in the
figure above).
cycle within this window must be terminated with an active READY signal.
Otherwise the controller hangs until the next reset. A timeout function is only
provided by the watchdog timer.
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External Bus Interface
2001-04-19
C161U