HD404669 Datasheet, PDF (51/142 Pages) Hitachi Semiconductor – Low-Voltage AS Microcomputers with On-Chip DTMF Generation Circuit

HD404669 Series
R Port
The R port consist of 38 input/output pins and 3 input pins that can be addressed in groups of 4 bits. Data
can be input using the LAR and LBR instructions, and data can be output using the LRA and LRB
instructions. Output data is stored in the port data register for the corresponding pin.
The R port data control registers (DCR0 to DCR4 and DCR6 to DCRA: $030 to $034, and $036 to $03A)
are used to turn the R port output buffers on and off. The DCR registers are mapped to addresses in the
RAM area. (figure 29.)
The R0₀ to R0₄ port pins have shared functions as the external interrupt input pins INT₁ to INT₄. Port mode
register B (PMRB $024) is used to set these pins to their peripheral function usage. (figure 31.)
The R4₀ port pin has a shared function as the EVND peripheral function pin. Port mode register C (PMRC:
$025) bit 1 (PMRC1) is used to switch the function of this pin. (figure 32.)
The R3₁ and R3₂ port pins have shared functions as the TOC and TOD peripheral function pins. Timer
mode register C2 (TMC2: $014) bits 0 to 2 (TMC20 to TMC22) and timer mode register D2 (TMD2: $015)
are used to set these pins to their peripheral function usage. (figures 33 and 34.)
The R4₁ to R4₃ port pins have shared functions as the SCK₁, SI₁, and SO₁ peripheral function pins. Serial
mode register 1A (SM1A: $005) bit 3 (SM1A3) and port mode register A (PMRA: $004) bits 0 and 1
(PMRA0 and PMRA1) are used to set these pins to their peripheral function usage. (figures 30 and 35.)
The R4₃/SO₁ pin can be set to function as an NMOS open drain output with the output buffer off.
Miscellaneous register (MIS: $00C) bit 2 (MIS2) is used for this setting. (figure 37.)
The RD₀ and RD₁ port pins have shared functions as the COMP₀ and COMP₁ peripheral function pins. The
compare enable register (CER: $018) is used to set these pins to their comparator pin functions. (figure 36.)
Port mode register A (PMRA: $004)
Bit
Initial value
Read/Write
Bit name
3
2
1
0
—
—
0
0
—
—
W
W
Not used Not used PMRA1 PMRA0
PMRA1
0
1
R4₂/SI₁ mode selection
R4₂
SI₁
PMRA0
0
1
R4₃/SO₁ mode selection
R4₃
SO₁
Figure 30 Port Mode Register A (PMRA)
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