20-668-0024 Rabbit Semiconductor, 20-668-0024 Datasheet - Page 97

• Manufacturer Part Number: 20-668-0024
• Description: IC CPU RABBIT4000 128-LQFP
• Manufacturer: Rabbit Semiconductor

Specifications of 20-668-0024

• Processor Type: Rabbit 4000 8-bit
• Speed: 60MHz
• Voltage: 2.5V, 2.7V, 3V, 3.3V
• Mounting Type: Surface Mount
• Package / Case: 128-LQFP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Features: -
• Other names: 20-668-0022; 316-1078

11.1 Overview
Parallel Port D is a byte-wide port with each bit programmable for data direction and drive
level. These are simple inputs and outputs controlled and reported in the Port D Data
Register (PDDR).
All of the Parallel Port D pins have alternate output functions, and all of them can be used
as inputs to various on-chip peripherals.
When used as outputs, the Parallel Port D bits are buffered, with the data written to PDDR
transferred to the output pins on a selected timing edge. Either the peripheral clock or the
outputs of Timer A1, Timer B1, or Timer B2 can be used for this function, with each nib-
ble of the port having a separate select field to control this timing. Each bit can either be
programmed as open-drain or driven high and low.
Because of the buffered nature of Parallel Port D, using a read-modify-write type of oper-
ation can lead to old data being written to PDDR. To alleviate this potential problem, each
bit of the port can be written individually using a separate address for each bit.
Parallel Port D acts as the upper byte of the data bus when the 16-bit mode is enabled; all
other functionality of Parallel Port D will be automatically disabled when 16-bit mode is
in effect.
Chapter 11 Parallel Port D
Pin Name
PD7
PD6
PD5
PD4
PD3
PD2
PD1
PD0
Table 11-1. Parallel Port D Pin Alternate Output Functions
Alt Out 0
SCLKD
SCLKC
TXA
TXB
IA7
IA6
IA7
IA6
Alt Out 1
I1
I7
I6
I5
I4
I3
I2
I0
11. P
TIMER C3
TIMER C2
TIMER C1
TIMER C0
Alt Out 2
PWM3
PWM2
PWM1
PWM0
ARALLEL
Alt Out 3
SCLKC
RCLKE
TCLKE
SCLKD
RCLKF
TCLKF
TXE
TXF
P
ORT
Data Bus
16-bit
D15
D14
D13
D12
D10
D11
D9
D8
D
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