
CHAPTER 2 PIN FUNCTIONS
Preliminary User’s Manual U16541EJ1V0UM
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(viii) A0 to A15 (address bus) … Output
These are 16-bit address output pins used during external access.
The output changes in
synchronization with the rising edge of the clock in the T1 state of the bus cycle. When the bus cycle
becomes inactive, these pins hold the address of the immediately preceding bus cycle.
(ix) INTP4 to INTP6 (interrupt request from peripherals) … Input
These are external interrupt request signal input pins.
(iix) KR6, KR7 (key return) … Input
These are key interrupt input pins. The operation is specified by the key return mode register (KRM)
in the input port mode.
(xi) SDA02 (serial data) … I/O
This is the serial transmit/receive data I/O pin for I
2C02 (SDA02 is valid only in the I2C bus version (Y
version)).
(xii) SCL02 (serial clock) … I/O
This is the serial clock data I/O pin for I
2C02 (SCL02 is valid only in the I2C bus version (Y version)).
(8) PCM0 to PCM3 (port CM) … 3-state I/O
PCM0 to PCM3 function as a 4-bit I/O port for which input and output can be set in 1-bit units.
In addition to I/O pins, these pins can also be used as the bus hold signal I/O in the control mode, bus clock
output, and the control signal (WAIT) that inserts waits into the bus cycle.
(a) Port mode
PCM0 to PCM3 can be set to input or output in 1-bit units using port mode register CM (PMCM).
(b) Control mode
(i)
HLDAK (hold acknowledge) … Output
This is an output pin for the acknowledge signal that indicates the high-impedance status for the
address bus, data bus, and control bus when the V850ES/SG2 receives a bus hold request.
The address bus, data bus, and control bus are high impedance while this signal is active.
(ii)
HLDRQ (hold request) … Input
This is an input pin by which an external device requests the V850ES/SG2 to release the address
bus, data bus, and control bus release requests. This pin accepts asynchronous input for CLKOUT.
When this pin is made active, the V850ES/SG2 sets the address bus, data bus, and control bus to
high impedance upon the end of the bus cycle currently being executed, or immediately if no bus
cycle is being executed, and the HLDAK signal is then made active and the bus is released.
(iii) CLKOUT (clock output) … Output
This pin outputs internally generated bus clocks.