20-668-0011 Rabbit Semiconductor, 20-668-0011 Datasheet - Page 139

• Manufacturer Part Number: 20-668-0011
• Description: IC MPU RABIT3000A 55.5MHZ128LQFP
• Manufacturer: Rabbit Semiconductor

Specifications of 20-668-0011

• Processor Type: Rabbit 3000 8-Bit
• Speed: 55.5MHz
• Voltage: 2.5V, 2.7V, 3V, 3.3V
• Mounting Type: Surface Mount
• Package / Case: 128-LQFP
• Data Bus Width: 8 bit
• Maximum Clock Frequency: 55.5 MHz
• Operating Supply Voltage: 1.8 V to 3.6 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• Minimum Operating Temperature: - 55 C
• Number Of Programmable I/os: 56
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Features: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant
• Other names: 316-1061

A sample clocked serial interrupt handler is shown below for Serial Port B.
Chapter 17 Serial Ports A – D
clocked_serb_isr::
rx_ready:
check_for_tx:
done:
push af
ioi ld a, (SASR)
bit 7,a
push af
jr
ioi ld a, (SADR)
; do something with received byte here
ld a, 0x41
ioi ld (SACR), a
pop af
bit 3,a
jr nz, done
; get next byte to be transmitted into A here
ioi ld (SADR), a
pop af
ipres
ret
z, check_for_tx
; save used registers
; get status
; check if byte ready in RX buffer
; save status for next check
; read byte and clear interrupt
; set bits 6-7 to 01, the other bits should
; represent the desired SACR setup
; start a new receive operation
; check if TX buffer was emptied
; load TX buffer with next byte and clear interrupt
; restore used registers
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