h8s-2158 Renesas Electronics Corporation., h8s-2158 Datasheet - Page 715

• Manufacturer Part Number: h8s-2158
• Description: Renesas 16-bit Single-chip Microcomputer H8s Family/h8s/2100 Series
• Manufacturer: Renesas Electronics Corporation.

19.5.5
Commands involving read data confirm the MMC status by the command arguments and
command responses, and then receive MMC information and flash memory data from the
MCDAT pin.
The number of bytes of flash memory to be read is a block size specified by CMD16, or if not
specified, reading is continued until it is aborted by CMD12M in multiblock transfer and stream
transfer. For multiblock transfer, the transfer is suspended at the end of to wait for every block the
instruction for continuing the command sequence.
Whether the command sequence is suspended or not during the command sequence depends on
the size of the block and receive data FIFO. The command sequence is executed without
suspending the data transfer when block size
multiblock transfer, the command sequence is suspended for every block. When block size >
receive data FIFO size in single-block transfer, the command sequence is suspended by FIFO full.
When the command sequence is suspended, data in the receive data FIFO is processed, and the
command sequence is then continued.
Figures 19.7 to 19.10 show examples of the command sequence for commands with read data.
Figure 19.11 shows the operational flow for commands with read data.
Settings needed to issue a command are made. Receive data FIFO is cleared.
The START bit in CMDSTRT is set to 1 to start command transmission. Command
transmission complete can be confirmed by the command transmission end interrupt (CMDI).
A command response is received from the MMC. If the MMC does not return the command
response, the command response is detected by the command timeout error (CTERI).
Read data from the MMC is detected.
The suspension inter-blocks in multiblock transfer and suspension according to the receive
data FIFO full are detected by the data transfer end interrupt (DTI) and FIFO full interrupt
(FFI), respectively. To continue the command sequence, the RD_CONTI bit in OPCR should
be set to 1. To abort the command sequence, the CMDOFF bit in OPCR should be set to 1, and
CMD12 should be issued.
Detection of the end of a command sequence depends on the command types. In multiblock
transfer of an extended command in SPI mode, the end of the command sequence is detected
by the block transfer end interrupt (BTI) after the desired number of blocks has been received.
In other commands, the end of the command sequence is detected by poling the BUSY flag in
CSTR or by the data transfer end interrupt (DTI).
Commands with Read Data
receive data FIFO size in single-block transfer. In
Section 19 Multimedia Card Interface (MCIF)
Rev. 3.00 Jan 25, 2006 page 663 of 872
REJ09B0286-0300