AT80C51SND1C-ROTIL Atmel, AT80C51SND1C-ROTIL Datasheet - Page 135

• Manufacturer Part Number: AT80C51SND1C-ROTIL
• Description: IC MCU FLASH MP3 DECODER 80-TQFP
• Manufacturer: Atmel
• Series: 80Cr

Specifications of AT80C51SND1C-ROTIL

• Core Processor: 8051
• Core Size: 8-Bit
• Speed: 40MHz
• Connectivity: I²C, IDE/ATAPI, MMC, SPI, UART/USART, USB
• Peripherals: Audio, I²S, MP3, PCM, POR, WDT
• Number Of I /o: 44
• Program Memory Type: ROMless
• Ram Size: 2.25K x 8
• Voltage - Supply (vcc/vdd): 2.7 V ~ 3.3 V
• Data Converters: A/D 2x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 80-TQFP, 80-VQFP
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Eeprom Size: -
• Program Memory Size: -
• Other names: AT80C51SND1CROTIL

18.2.2
18.3
4109L–8051–02/08
Synchronous Mode (Mode 0)
Internal Baud Rate Generator
Figure 18-1. Timer 1 Baud Rate Generator Block Diagram
When using the Internal Baud Rate Generator, the Baud Rate is derived from the overflow of the
timer. As shown in Figure 18-2 the Internal Baud Rate Generator is an 8-bit auto-reload timer
fed by the peripheral clock or by the peripheral clock divided by 6 depending on the SPD bit in
BDRCON register (see Table 130). The Internal Baud Rate Generator is enabled by setting BBR
bit in BDRCON register. SMOD1 bit in PCON register allows doubling of the generated baud
rate.
Figure 18-2. Internal Baud Rate Generator Block Diagram
Mode 0 is a half-duplex, synchronous mode, which is commonly used to expand the I/0 capabil-
ities of a device with shift registers. The transmit data (TXD) pin outputs a set of eight clock
pulses while the receive data (RXD) pin transmits or receives a Byte of data. The 8-bit data are
transmitted and received least-significant bit (LSB) first. Shifts occur at a fixed Baud Rate (see
Section "Baud Rate Selection (Mode 0)", page 137). Figure 18-3 shows the serial port block dia-
gram in Mode 0.
CLOCK
CLOCK
INT1
PER
PER
T1
GATE1
TMOD.7
TCON.6
TR1
÷ 6
÷ 6
BDRCON.1
SPD
TMOD.6
C/T1#
0
1
0
1
BDRCON.4
BRR
(8 bits)
(8 bits)
(8 bits)
(8 bits)
BRG
BRL
TH1
TL1
Overflow
Overflow
AT8xC51SND1C
÷ 2
÷ 2
SMOD1
SMOD1
PCON.7
CLOCK
PCON.7
CLOCK
IBRG
T1
0
1
0
1
To serial
Port
To serial
Port
135