Datasheet

CHAPTER 9 A/D CONVERTER ( μ PD78F920x ONLY)
User’s Manual U18172EJ3V0UD
165
(4) 8-bit A/D conversion result register (ADCRH)
This register is an 8-bit register that stores the A/D conversion result. It stores the higher 8 bits of a 10-bit
resolution result.
ADCRH can be read by an 8-bit memory manipulation instruction.
Reset signal generation makes ADCRH undefined.
Figure 9-7. Format of 8-Bit A/D Conversion Result Register (ADCRH)
Symbol
ADCRH
76543210
Address: FF1AH After reset: Undefined R
(5) Port mode register 2 (PM2) and port mode control register 2 (PMC2)
When using the when the P20/ANI0/TI000/TOH1, P21/ANI1/TI010/TO00/INTP0, P22/ANI2, and P23/ANI3 pins
for analog input, set PM20 to PM23 and PMC20 to PMC23 to 1. At this time, the output latches of P20 to P23
may be 0 or 1.
PM2 and PMC2 are set by a 1-bit or 8-bit memory manipulation instruction.
Reset signal generation sets PM2 to 00H and clears PMC2 to FFH.
Figure 9-8. Format of Port Mode Register 2 (PM2)
Address: FF22H After reset: FFH R/W
Symbol 7 6 5 4 3 2 1 0
PM2 1 1 1 1 PM23 PM22 PM21 PM20
PM2n Pmn pin I/O mode selection (n = 0 to 3)
0 Output mode (output buffer on)
1 Input mode (output buffer off)
Figure 9-9. Format of Port Mode Control Register 2 (PMC2)
Address: FF84H After reset: 00H R/W
Symbol 7 6 5 4 3 2 1 0
PMC2 0 0 0 0 PMC23 PMC22 PMC21 PMC20
PMC2n Operation mode specification (n = 0 to 3)
0 Port/Alternate-function (except A/D converter) mode
1 A/D converter mode
Caution If PMC20 to PMC23 are set to 1, the P20/ANI0/TI000/TOH1, P21/ANI1/TIO10/TO00/INTP0,
P22/ANI2, and P23/ANI3 pins cannot be used for any purpose other than the A/D converter
function.
Be sure to set 0 to the Pull-up resistor option register of the pin set in A/D converter mode.