NEC V850ES/SA2 UPD703201 Manual page 52

(11) PCT0, PCT1, PCT4 to PCT7 (Port CT) (V850ES/SA2) ... 3-state I/O
PCT0 to PCT7 (Port CT) (V850ES/SA3) ... 3-state I/O
[V850ES/SA2]
Port CT is a 6-bit port that can be set to the input or output mode in 1-bit units.
Besides functioning as I/O port pins, in the control mode PCT0, PCT1, and PCT4 to PCT7 also operate as the
control signal output pins when the memory is expanded externally.
(a) Port mode
PCT0, PCT1, and PCT4 to PCT7 can be set to the input or output mode in 1-bit units by using port mode
register CT (PMCT).
(b) Control mode
(i) WR0 (write strobe low level data) ... Output
This is the write strobe signal output pin for the lower data of the external 16-bit data bus.
(ii) WR1 (write strobe high level data) ... Output
This is the write strobe signal output pin for the higher data of the external 16-bit data bus.
(iii) RD (read strobe) ... Output
This is the read strobe signal output pin for the external 16-bit data bus.
(iv) ASTB (address strobe) ... Output
This is the latch strobe signal output pin of the external address bus. The output signal goes low at
the falling edge of the T1 state in the bus cycle, and goes high at the falling edge of the T3 state. It is
high when the bus cycle is not active.
[V850ES/SA3]
Port CT is an 8-bit port that can be set to the input or output mode in 1-bit units.
Besides functioning as I/O port pins, in the control mode PCT0 to PCT7 also operate as the control signal
output pins when the memory is expanded externally.
(a) Port mode
PCT0 to PCT7 can be set to the input or output mode in 1-bit units by using port mode register CT
(PMCT).
(b) Control mode
(i) WR0 (write strobe low level data) ... Output
This is the write strobe signal output pin for the lower data of the external 16-bit data bus.
(ii) WR1 (write strobe high level data) ... Output
This is the write strobe signal output pin for the higher data of the external 16-bit data bus.
52
CHAPTER 2 PIN FUNCTIONS
Preliminary User's Manual U15905EJ1V0UD