upd70f3017ay Renesas Electronics Corporation., upd70f3017ay Datasheet - Page 51

• Manufacturer Part Number: upd70f3017ay
• Description: V850/sa1tm 32-/16-bit Single-chip Microcontroller
• Manufacturer: Renesas Electronics Corporation.

(v) ASTB (Address strobe) ··· output
(vi) HLDAK (Hold acknowledge) ··· output
(vii) HLDRQ (Hold request) ··· input
(viii) WRL (Write strobe low level data) ··· output
(ix) WRH (Write strobe high level data) ··· output
(x) RD (Read strobe) ··· output
This is an output pin for the external address bus’s latch strobe signal. Output becomes active (low
level) in synchronization with the falling edge of the clock during the T1 state of the bus cycle, and
becomes inactive (high level) in synchronization with the falling edge of the clock during the T3 state of
the bus cycle. Output becomes inactive when the timing sets the bus cycle as inactive.
This is an output pin for the acknowledge signal that indicates high impedance status for the address
bus, data bus, and control bus when the V850/SA1 receives a bus hold request.
The address bus, data bus, and control bus are set to high impedance status when this signal is active.
This is an input pin by which an external device requests the V850/SA1 to release the address bus, data
bus, and control bus. This pin accepts asynchronous input for CLKOUT. When this pin is active, the
address bus, data bus, and control bus are set to high impedance status. This occurs either when the
V850/SA1 completes execution of the current bus cycle or immediately if no bus cycle is being
executed, then the HLDAK signal is set as active and the bus is released.
This is a write strobe signal output pin for the lower data in the external 16-bit data bus. Output occurs
during the write cycle, similar to DSTB.
This is a write strobe signal output pin for the higher data in the external 16-bit data bus. Output occurs
during the write cycle, similar to DSTB.
This is a read strobe signal output pin for the external 16-bit data bus. Output occurs during the read
cycle, similar to DSTB.
CHAPTER 2 PIN FUNCTIONS
User’s Manual U12768EJ4V1UD
51