AT80C51SND1C-ROTIL Atmel, AT80C51SND1C-ROTIL Datasheet - Page 117

• 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

16.5.2
16.6
4109L–8051–02/08
Data Line Controller
Command Receiver
•
Figure 16-14 summarizes the command transmission flow.
As soon as command transmission is enabled, the CFLCK flag in MMSTA is set indicating that
write to the FIFO is locked. This mechanism is implemented to avoid command overrun.
The end of the command transmission is signalled to you by the EOCI flag in MMINT register
becoming set. This flag may generate an MMC interrupt request as detailed in Section "Inter-
rupt", page 123. The end of the command transmission also resets the CFLCK flag.
User may abort command loading by setting and clearing the CTPTR bit in MMCON0 register
which resets the write pointer to the transmit FIFO.
Figure 16-14. Command Transmission Flow
The end of the response reception is signalled to you by the EORI flag in MMINT register. This
flag may generate an MMC interrupt request as detailed in Section "Interrupt", page 123. When
this flag is set, 2 other flags in MMSTA register: RESPFS and CRC7S give a status on the
response received. RESPFS indicates if the response format is correct or not: the size is the one
expected (48 bits or 136 bits) and a valid End bit has been received, and CRC7S indicates if the
CRC7 computation is correct or not. These Flags are cleared when a command is sent to the
card and updated when the response has been received.
User may abort response reading by setting and clearing the CRPTR bit in MMCON0 register
which resets the read pointer to the receive FIFO.
According to the MMC specification delay between a command and a response (formally N
parameter) can not exceed 64 MMC clock periods. To avoid any locking of the MMC controller
when card does not send its response (e.g. physically removed from the bus), user must launch
a time-out period to exit from such situation. In case of time-out user may reset the command
controller and its internal state machine by setting and clearing the CCR bit in MMCON2
register.
This time-out may be disarmed when receiving the response.
The data line controller is based on a 16-Byte FIFO used both by the data transmitter channel
and by the data receiver channel.
CRCDIS bit in MMCON0 register to indicate whether the CRC7 included in the response will
be computed or not. In order to avoid CRC error, CRCDIS may be set for response that do
not include CRC7.
Configure Response
Transmission
RESPEN = X
Command
CRCDIS = X
RFMT = X
Transmit Command
MMCMD = argument
Load Command in
MMCMD = index
CMDEN = 1
CMDEN = 0
Buffer
AT8xC51SND1C
117
CR