UPD78F0034BGC-8BS-A Renesas Electronics America, UPD78F0034BGC-8BS-A Datasheet - Page 411

• Manufacturer Part Number: UPD78F0034BGC-8BS-A
• Description: MCU 8-Bit 78K0 CISC 32KB Flash 2.5V/3.3V/5V 64-Pin LQFP
• Manufacturer: Renesas Electronics America

Specifications of UPD78F0034BGC-8BS-A

• Package: 64LQFP
• Family Name: 78K0
• Maximum Speed: 12 MHz
• Ram Size: 1 KB
• Program Memory Size: 32 KB
• Operating Supply Voltage: 2.5|3.3|5 V
• Data Bus Width: 8 Bit
• Program Memory Type: Flash
• Number Of Programmable I/os: 51
• Interface Type: 3-Wire/UART
• On-chip Adc: 8-chx10-bit
• Operating Temperature: -40 to 85 °C
• Number Of Timers: 3

(5) Program status word (PSW)
PSW
The program status word is a register to hold the instruction execution result and the current status for an interrupt
request. The IE flag to set maskable interrupt enable/disable and the ISP flag to control nesting processing are
mapped.
Besides 8-bit read/write, this register can carry out operations with a bit manipulation instruction and dedicated
instructions (EI and DI). When a vectored interrupt request is acknowledged, if the BRK instruction is executed,
the contents of PSW are automatically saved into a stack and the IE flag is reset to 0. If a maskable interrupt
request is acknowledged, the contents of the priority specification flag of the acknowledged interrupt are
transferred to the ISP flag. The PSW contents are also saved into the stack with the PUSH PSW instruction.
They are restored from the stack with the RETI, RETB, and POP PSW instructions.
RESET input sets PSW to 02H.
IE
7
6
Z
RBS1
5
AC
4
Figure 19-6. Program Status Word Format
RBS0
3
CHAPTER 19 INTERRUPT FUNCTIONS
2
0
User’s Manual U14046EJ5V0UD
ISP
1
CY
0
ISP
IE
0
1
0
1
Used when normal instruction is executed
After reset
02H
High-priority interrupt servicing (Low-priority
interrupt disable)
Interrupt request not acknowledged, or low-
priority interrupt servicing (All maskable
interrupts enable)
Disable
Enable
Interrupt request acknowledge enable/disable
Priority of interrupt currently being serviced
409