80C554 Datasheet, PDF (23/76 Pages) NXP Semiconductors – 80C51 8-bit microcontroller . 6 clock operation 16K/512 OTP/ROM/ROMless, 7 channel 10 bit A/D, I2C, PWM, capture/compare, high I/O, 64L LQFP

Philips Semiconductors
80C51 8-bit microcontroller – 6 clock operation
16K/512 OTP/ROM/ROMless, 7 channel 10 bit A/D, I²C, PWM,
capture/compare, high I/O, 64L LQFP
Preliminary specification
80C554/83C554/87C554
PWM0
f_OSC
PRESCALER
PWMP
8-BIT COMPARATOR
8-BIT COUNTER
8-BIT COMPARATOR
OUTPUT
BUFFER
PWM0
OUTPUT
BUFFER
PWM1
PWM1
Figure 19. Functional Diagram of Pulse Width Modulated Outputs
ADC0
ADC1
ADC2
ADC3
ADC4
ADC5
ADC6
ANALOG INPUT
MULTIPLEXER
10-BIT A/D CONVERTER
SU01448
STADC
+
ANALOG REF.
–
ANALOG SUPPLY
ANALOG GROUND
ADCON
0
1
2
3
4
5
6
7
0
1
2
3
4
5
6
7
ADCH
INTERNAL BUS
Figure 20. Functional Diagram of Analog Input Circuitry
SU01467
10-Bit Analog-to-Digital Conversion: Figure 21 shows the
elements of a successive approximation (SA) ADC. The ADC
contains a DAC which converts the contents of a successive
approximation register to a voltage (VDAC) which is compared to
the analog input voltage (Vin). The output of the comparator is fed to
the successive approximation control logic which controls the
successive approximation register. A conversion is initiated by
setting ADCS in the ADCON register. ADCS can be set by software
only or by either hardware or software.
The software only start mode is selected when control bit ADCON.5
(ADEX) = 0. A conversion is then started by setting control bit
ADCON.3 (ADCS). The hardware or software start mode is selected
when ADCON.5 = 1, and a conversion may be started by setting
ADCON.3 as above or by applying a rising edge to external pin
STADC. When a conversion is started by applying a rising edge, a
low level must be applied to STADC for at least one machine cycle
followed by a high level for at least one machine cycle.
2000 Nov 10
23