User manual

Page 9
Document No. 80-15151 Issue 6 HEBER LTD
Pins controlled by the Serial module are allocated as follows:
Table 3. Allocation of MC68340 Pins Controlled by Serial Module
PIN NO. I/O FUNCTION
RXDA 33 I RX DATA Channel A, P1, Pin 2 (RS232 level) &
To IO Expansion Connector P14, Pin c9 (TTL level)
TXDA 32 O TX DATA Channel A, P1, Pin 3 (RS232 level) &
To IO Expansion Connector P14, Pin c10 (TTL level)
RXDB 25 I RX DATA Channel B, DATAPORT P2 (RS232 level)
TXDB 24 O TX DATA Channel B, DATAPORT P2 (RS232 level)
OP0/RTSA- 29 O RTS Channel A, P1, Pin 5 (RS232 level) &
To IO Expansion Connector P14, Pin c12 (TTL level)
OP1/RTSB- 23 O RTS Channel B, DATAPORT P2 (RS232 level)
OP4/RXRDYA- 27 O SFX Channel #1 – U8, Pin S1 (Select Sample Rate)
OP6/TXRDYA- 26 O SFX Channel #1 – U8, Pin S2 (Select Sample Rate)
CTSA- 28 I CTS DUART Channel A, P1, Pin 4 (RS232 level) &
To IO Expansion Connector P14, Pin c11 (TTL level)
CTSB- 22 I CTS Channel B, DATAPORT P2 (RS232 level)
5.4.5 Timer Module
The Timer Module provides 2 General Purpose Timers.
The Pluto 5 Board uses these to provide a variable duty-cycle signals on TOUT1 and TOUT2 that is
used to control the volume setting on each channel of the TDA7057AQ Stereo Audio Amplifier.
Timer 1 (TOUT1) controls the volume of Sound Channel #1. Timer 2 TOUT2) controls the volume of
Sound Channel #2 if it is fitted. If Sound Channel #2 is not fitted, then Timer 2 may be used for other
purposes.
See Section 6.9, “Making Sounds” for detailed information on the operation of the Volume Controls.
Pins TGATE1- and TGATE2- are allocated as general purpose inputs which are used to read the SCL
and SDA lines on the External I
2
C Connector, P13.
Pins controlled by the Timer Module are allocated as follows:
Table 4. Allocation of MC68340 Pins Controlled by Timer Module
PIN NO. I/O FUNCTION
TGATE1- 79 I Read External I
2
C line SCL on P13, Pin 3 (inverted)
TIN1 81 I Not Used – Strapped To Vcc
TOUT1 80 O Variable Duty Cycle Volume Control SFX Channel #1
TGATE2- 36 I Read External I
2
C Line SDA on P13, Pin 2 (inverted)
TIN2 34 I Not Used - Strapped To Vcc
TOUT2 35 O Variable Duty Cycle Volume Control SFX Channel #2