mb91101 Fujitsu Microelectronics, Inc., mb91101 Datasheet - Page 36

• Manufacturer Part Number: mb91101
• Description: 32-bit Risc Microcontroller Cmos
• Manufacturer: Fujitsu Microelectronics, Inc.

36
MB91101/MB91101A
1. I/O Ports
PERIPHERAL RESOURCES
There are 2 types of I/O port register structure; port data register (PDR0 to PDRF) and data direction register
(DDR0 to DDRF), where bits PDR0 to PDRF and bits DDR0 to DDRF corresponds respectively. Each bit on
the register corresponds to an external pin. In port registers input/output register of the port configures input/
output function of the port, while corresponding bit (pin) configures input/output function in data direction regis-
ters. Bit “0” specifies input and “1” specifies output.
• For input (DDR = “0”) setting;
• For output (DDR = “1”) setting;
• Block diagram
PDR reading operation: reads PDR value.
PDR writing operation: outputs PDR value to corresponding external pin.
PDR reading operation: reads level of corresponding external pin.
PDR writing operation: writes set value to PDR.
(Data direction register)
(Port data register)
PDR read
PDR
DDR
Resource output
Resource output enable
0
1
0
1
Resource input
Pin