HD6435348R Hitachi Semiconductor, HD6435348R Datasheet - Page 163

• Manufacturer Part Number: HD6435348R
• Description: Single-Chip Microcomputer
• Manufacturer: Hitachi Semiconductor

SYSCR1 selects the functions of four of the port 1 pins. It also selects the input edge of the NMI
pin.
At a reset and in the hardware standby mode, SYSCR1 is initialized to H'87. It is not initialized in
the software standby mode.
Bit 7—Reserved: This bit cannot be modified and is always read as 1.
Bit 6—Interrupt Request 1 Enable (IRQ
Bit 6
IRQ
0
1
Bit 5—Interrupt Request 0 Enable (IRQ
Bit 5
IRQ
0
1
Bit 4—Nonmaskable Interrupt Edge (NMIEG): This bit selects the input edge of the NMI pin.
It is not related to port 0.
Bit 4
NMIEG
0
1
Bit 3—Bus Release Enable (BRLE): This bit selects the functions of pins P1
valid only in the expanded modes (modes 1, 2, 3, and 4). In the single-chip mode, pins P1
P1
3
1
0
function as input/output pins regardless of the value of the BRLE bit.
E
E
Description
P1
P1
the CPU can still read the pin status by reading P1DR.)
Description
P1
P1
the CPU can still read the pin status by reading P1DR.)
Description
A nonmaskable interrupt is generated on the falling edge
of the input at the NMI pin.
A nonmaskable interrupt is generated on the rising edge
of the input at the NMI pin.
6
6
5
5
functions as an input/output pin.
functions as the IRQ
functions as an input/output pin.
functions as the IRQ
1
0
input pin, regardless of the value set in P1
input pin, regardless of the value set in P1
1
0
E): This bit selects the function of pin P1
E): This bit selects the function of pin P1
146
2
6
5
(Initial value)
(Initial value)
(Initial value)
and P1
DDR. (However,
DDR. (However,
6
5
.
.
3
. It is
2
and