
III PERIPHERAL BLOCK: SINGLE MASTER I2C-BUS
EPSON
S1C33T01 FUNCTION PART
B-III-9-8
Read DMA request interrupt factor
When a DMA transfer is set up by the single-master I
2 C-bus core DMA transfer mode setting register
Dx_MD[1:0], and TRNSx[2:0] in the single-master I
2 C-bus core control register is set to "011" (data receive),if
the interrupt is enabled by setting the FI2CRx flag in the single-master I
2 C-bus core Ch. 0/1 factor flag register,
a read DMA request interrupt will be issued.
This interrupt factor can be used to start HSDMA or IDMA operations.
Write DMA request interrupt factor
When a DMA transfer is set up by the single-master I
2 C-bus core DMA transfer mode setting register
Dx_MD[1:0], and TRNSx[2:0] in the single-master I
2 C-bus core control register is set to "100" (data transfer),
if the interrupt is enabled by setting the FI2CWx flag in the single-master I
2 C-bus core Ch. 0/1 factor flag
register, a read DMA request interrupt will be issued.
This interrupt factor can be used to start HSDMA or IDMA operations.
Interrupt controller control registers
Table 9.5 lists the interrupt controller control register that are provided for each interrupt system (channel).
Table 9.5
Interrupt Controller Control Registers
Ch.
Interrupt factor
Interrupt factor flag
Interrupt enable
register
Interrupt priority register
0
Command
complete/error
FI2CI0(D0/0x402B2)
EI2CI0(D0/0x402B1)
PI2C0[2:0](D[2:0] / 0x402B0)
Read DMA request
FI2CR0(D1/0x402B2)
EI2CR0(D1/0x402B1)
Write DMA request
FI2CW0(D2/0x402B2)
EI2CW0(D2/0x402B1)
1
Command
complete/error
FI2CI1(D3/0x402B2)
EI2CI1(D3/0x402B1)
PI2C1[2:0](D[6:4] / 0x402B0)
Read DMA request
FI2CR1(D4/0x402B2)
EI2CR1(D4/0x402B1)
Write DMA request
FI2CW1(D5/0x402B2)
EI2CW1(D5/0x402B1)
When one of the previously described interrupt factors occurs, the corresponding interrupt flag is set to "1". If
the interrupt enable register bit corresponding to that interrupt factor is set to "1", an interrupt request is issued.
Particular interrupt factors can be disabled by setting the corresponding bit in the interrupt enable register to "0".
The interrupt flags are always set to "1" when the corresponding interrupt conditions are established, regardless
of the interrupt enable register setting, i.e., even if the corresponding bit is set to "0".
The interrupt priority register sets the interrupt priority level (0 to 7) for each interrupt system. For an interrupt
request to be issued to the CPU, there must be no outstanding interrupt factors with a higher priority.
Also note that the CPU will only accept an input interrupt request if the PSR IE bit is set to "1" (interrupts
enabled) and IL is set to a value smaller than the input interrupt level set in the interrupt priority register.
See the "ITC (interrupt controller)" section for details on these interrupt control registers and operation when an
interrupt occurs.
Intelligent DMA
The read DMA request interrupt and the write DMA request interrupt can start intelligent DMA (IDMA)
operation. This allows continuous transmit/receive operations to be performed using DMA transfers between
memory and the transmit/receive data registers.
The IDMA channel numbers assigned to each factor are as follows.
IDMA Ch.
Ch. 0 read DMA request interrupt:
0x36
Ch. 0 write DMA request interrupt:
0x37
Ch. 1 read DMA request interrupt:
0x38
Ch. 1 write DMA request interrupt:
0x39
The IDMA enable and request bits listed in Table 9.6 must be set to "1" to start an IDMA operation. Also note
that in addition to setting the single-master I
2 C-bus DMA mode register and the single-master I2C-bus DMA
counter, the IDMA transfer conditions must be set up in the IDMA itself.