MC68HC912DG128 Datasheet, PDF (269/452 Pages) Motorola, Inc – Microcontrollers

Freescale Semiconductor, Inc.
Multiple Serial Interface
Serial Peripheral Interface (SPI)
SPC0 — Serial Pin Control 0
This bit decides serial pin configurations with MSTR control bit.
Pin Mode
SPC0⁽¹⁾
MSTR
MISO⁽²⁾ MOSI⁽³⁾
SCK⁽⁴⁾
#1
Normal
0
#2
0
Slave Out Slave In SCK In
1
Master In Master Out SCK Out
#3
Bidirectional
1
#4
0
Slave I/O GPI/O
SCK In
1
GPI/O Master I/O SCK Out
1. The serial pin control 0 bit enables bidirectional configurations.
2. Slave output is enabled if DDS4 = 1, SS = 0 and MSTR = 0. (#1, #3)
3. Master output is enabled if DDS5 = 1 and MSTR = 1. (#2, #4)
4. SCK output is enabled if DDS6 = 1 and MSTR = 1. (#2, #4)
5. SS output is enabled if DDS7 = 1, SSOE = 1 and MSTR = 1. (#2, #4)
SS⁽⁵⁾
SS In
SS I/O
SS In
SS I/O
Bit 7
6
5
4
3
2
1
Bit 0
0
0
0
0
0
SPR2
SPR1
SPR0
RESET:
0
0
0
0
0
0
0
0
SP0BR — SPI Baud Rate Register
$00D2
Read anytime. Write anytime.
At reset, E Clock divided by 2 is selected.
SPR[2:0] — SPI Clock (SCK) Rate Select Bits
These bits are used to specify the SPI clock rate.
Table 14-4. SPI Clock Rate Selection
SPR2 SPR1 SPR0
0
0
0
0
0
1
0
1
0
0
1
1
1
0
0
1
0
1
1
1
0
1
1
1
E Clock
Divisor
2
4
8
16
32
64
128
256
Frequency at Frequency at
E Clock = 4 MHz E Clock = 8 MHz
2.0 MHz
4.0 MHz
1.0 MHz
2.0 MHz
500 kHz
1.0 MHz
250 kHz
500 KHz
125 kHz
250 KHz
62.5 kHz
125 KHz
31.3 kHz
62.5 KHz
15.6 kHz
31.3 KHz
MC68HC912DG128 — Rev 3.0
MOTOROLA
Multiple Serial Interface
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Technical Data
269