HT46RU67 Holtek Semiconductor Inc., HT46RU67 Datasheet - Page 45

• Manufacturer Part Number: HT46RU67
• Description: Ht46ru67/ht46cu67 -- A/d Type 8-bit Mcu With Lcd
• Manufacturer: Holtek Semiconductor Inc.

Serial Interface
Serial interface function has four basic signals included. They are SDI (serial data input), SDO (serial data output), SCK
(serial clock) and SCS (slave select pin).
Note: SCS can be named SCS in the design note.
Two registers (SBCR and SBDR) unique to serial inter-
face provide control, status, and data storage.
Rev. 1.00
SBCR: Serial bus control register
Bit7 (CKS) clock source selection: f
as 0
Bit6 (M1), Bit5 (M0) master/slave mode and baud rate
selection
M1, M0: 00
01
10
11
Bit4 (SBEN)
Enable: (SCS dependent on CSEN bit)
Disable
(SCKB= 0 ) and waiting for writing data to SBDR
(TXRX buffer)
Master mode: write data to SBDR (TXRX buffer)
start transmission/reception automatically
Master mode: when data has been transferred, set
TRF
Slave mode: when an SCK (and SCS dependent on
CSEN) is received, data in TXRX buffer is
shifted-out and data on SDI is shifted-in.
SLAVE MODE
MASTER MODE, BAUD RATE= f
MASTER MODE, BAUD RATE= f
MASTER MODE, BAUD RATE= f
enable: SCK, SDI, SDO, SCS= 0
serial bus enable/disable (1/0)
SIO
=f
SIO
SIO
SYS
/4
/16
/4, select
SIO
45
SBDR: Serial bus data register
Data written to SBDR
only
Data read from SBDR
Operating Mode description:
Master transmitter: clock sending and data I/O started
by writing SBDR
Master clock sending started by writing SBDR
Slave transmitter: data I/O started by clock received
Slave receiver: data I/O started by clock received
Disable: SCK (SCK), SDI, SDO, SCS floating
Bit3 (MLS)
Bit2 (CSEN)
able/disable (SCS), when CSEN=0, SCSB is float-
ing.
Bit1 (WCOL)
SBDR (TXRX buffer) when data is transferred,
writing will be ignored if data is written to SBDR
(TXRX buffer) when data is transferred.
Bit0 (TRF)
used to generate an interrupt.
Note: data receiving is still working when the MCU
enters HALT mode.
MSB or LSB (1/0) shift first control bit
data transferred or data received
HT46RU67/HT46CU67
this bit is set to 1 if data is written to
serial bus selection signal en-
read from SBDR only
write data to TXRX buffer
February 27, 2008