|
HD404328 Datasheet, PDF (43/96 Pages) Hitachi Semiconductor – 4 BIT SINGLE CHIP MICROCOMPUTER | |||
|
◁ |
HD404328 Series
D Port (D0âD10): Consist of 9 input/output pins and 2 input pins. Pins D0âD7 are high-current I/O pins, D8
is an ordinary input/output pin, and D9 and D10 are input-only pins. These pins are set by the SED and
SEDD instructions, reset by the RED and REDD instructions, and tested by the TD and TDD instructions.
The operating modes of D8âD10 are set by bits 2 and 3 of port mode register A (PMRA) and bits 0 and 1 of
port mode register B (PMRB), as shown in figure 24. The on/off status of the output buffer is controlled by
D port data control registers (DCRB, DCRC, and DCRD) that are mapped to memory addresses.
R Ports: Accessed in 4-bit units. Data is input to these ports by the LAR and LBR instructions and output
from them by the LRA and LRB instructions. The on/off status of the output buffers of the R ports are
controlled by R port data control registers (DCR0âDCR5) that are mapped to memory addresses.
Pins R10âR13 are multiplexed with pins SCK, SI, SO, and BUZZ, respectively. The operating modes of
these pins are controlled by bit 3 of the serial mode register (SMR), bits 1 and 0 of port mode register A
(PMRA), and bit 2 of port mode register C (PMRC), as shown in figure 24.
Ports R2âR5 are multiplexed with SEG1âSEG16. The functions of these pins must be specified by the
LCD output register (LOR: $015).
41
|
▷ |