TStik multiplexes P1.1/P5.0 and P1.0/P5.1 to these pins, under control of the TStik configuration register.
P1.1 can be used as I2C clock or as a general-purpose bidirectional pin.
P5.0 can be used as CAN TX line or as a general-purpose bidirectional pin.
P1.0 can be used as I2C data or as a general-purpose bidirectional pin.
P5.1 can be used as CAN RX line or as a general-purpose bidirectional pin.

TStik2 supports dedicated I2C on SIMM72.21 and 22, so if you want to also use CAN at the same moment, use these pins for CAN only.

TStik 2: Serial1 can be used for 1-Wire or as asynchronous serial. TTL-level TX1 and RX1 are available on the same edge contacts as TINI390. Serial1 mode is controlled by the TStik Configuration Register and the EN2480 signal (SIMM72.26) Since these signals come from the CPLD they are not general purpose I/O pins. See the Configuration Register and TStik API documentation for more details.

1. When 80C400 reset input (RST) is asserted due to:
   1. 5V power failure (VCC <= 4.0 V) at the Simm72 connector. This gives TStik advance indication of a coming power failure before its local 3.3V supply is affected.
   2. DTR reset from Serial0, used by JavaKit and typical socket board reset pushbuttons (STEP, TILT, Dallas EXX)
   3. Simm72.24 CPURST(H) input
2. during 80C400 crystal warmup
3. following 80C400 power on or STOP mode
4. during a watchdog timer reset (only two clock cycles according to the 80C400 data sheet)
5. during an oscillator failure (if OFD==1)
6. whenever the DS80C400 voltage comparators detect that VCC1 (1.8V) or VCC3 (3.3V) are out of tolerance

Since it is derived from RSTOL, PRST remains high while any reset sources are asserted (this is typically 4 to 140 msec). In the case of the DS80C400 watchdog timeout PRST is only asserted for two clock cycles (135 nsec with a 14.7456 MHz crystal).

PRST can also be asserted under program control through the TStik configuration register.

TStik2 adds I2C signals to these pins so that you can use CAN and I2C at the same time. This is a powerful new feature not available on any other TINI platform (as far as we know). If you wish to use both CAN and I2C, you will want to use these pins as dedicated I2C and pins 10,11 as dedicated CAN. These signals are connected directly to the C400 so if you are not using I2C, you can use them as general-purpose bidirectional pins. Note that these pins are always connected to C400 P1.1 and P1.0, even when pinsSIMM72.10 and 11 are in I2C mode (so don't try to drive 10/11 and 21/22 separately when 10/11 are in I2C mode).

Dual-purpose pins. Can be used as SPI slave chip selects or as general-purpose bidirectional pins. (On TINI400 these are not usable as peripheral chip selects because merging code and data space on CE0 and CE1 prevents such use.) In order to use these pins (and MISO, MOSI and SCK) as SPI signals you must use SPI support software from Dallas or Systronix (or write your own).

The Dallas SPI package uses these pins:
P5.4 (PCE0\) = SCK (SPI clock)
P5.5 (PCE1\) = MOSI (Master Out, Slave In)
P5.6 (PCE2\) = MISO (Master In, Slave Out)
P5.7 (PCE3\) = SS (Slave select)

The Systronix SPI package uses these pins:
P6.1(CE5\) = MOSI (Master Out, Slave In)
P6.2(CE6\) = MISO (Master In, Slave Out)
P6.0(CE4\) = SCK (SPI clock)
P5.4 (PCE0\) = SCS0 (Slave select 0)
P5.5 (PCE1\) = SCS1 (Slave select 1)
P5.6 (PCE2\) = SCS2 (Slave select 2)
P5.7 (PCE3\) = SCS3 (Slave select 3)

NOTES