SPRUIU1C July 2020 – February 2024 DRA821U , DRA821U-Q1
Table 12-4124 lists the GPMC subsystem input/output (I/O) pins.
Module Pin | Device Level Signal | I/O(1) | Description | Module Pin Reset Value(2) |
---|---|---|---|---|
GPMC0 | ||||
A[22-0] | GPMC0_A[22-0] | O | 23-bit output address bus | - |
A[16-1]/D[15-0] | GPMC0_AD[15-0] | I/O | Multiplexed address/data | - |
nCS[3-0] | GPMC0_CSn[3-0] | O | Chip-selects (active low) | - |
CLK | GPMC0_CLKOUT | O | Clock generated for the external memory or device. For more information, see Figure 12-2078. | - |
RET_CLK | ||||
N/A | GPMC0_FCLK_MUX | O | Free running clock. GPMC functional clock (GPMC0_FCLK) propagated on a device pad. For more information on the GPMC0_FCLK_MUX integration, see Figure 12-2078. | - |
nADV/ALE | GPMC0_ADVn_ALE | O | Address valid (active low). Also used as address latch enable (active high) for NAND protocol memories. | - |
nOE/nRE | GPMC0_OEn_REn | O | Output enable (active low). Also used as read enable (active low) for NAND protocol memories. | - |
nWE | GPMC0_WEn | O | Write enable (active low) | - |
nBE0/CLE | GPMC0_BE0n_CLE | O | Lower-byte enable (active low). Also used as command latch enable for NAND protocol memories. | - |
nBE1 | GPMC0_BE1n | O | Upper-byte enable (active low) | - |
WAIT[1-0] | GPMC0_WAIT[1-0] | I | External wait signal for NOR and NAND protocol memories. Can be mapped on any of the chip-selects. | - |
nWP | GPMC0_WPn | O | Write protect (active low) | - |
DIR | GPMC0_DIR | O | This signal can be used to control an external buffer direction. Also controls the signal direction of D[15-0]. Low during transmit (for write access: data OUT from GPMC0 to memory). High during receive (for read access: data IN from memory to GPMC0). | - |
For GPMC output clock signal (CLK) to work properly, the RXACTIVE bit of the appropriate CTRLMMR_PADCONFIGy registers should be set to 0x1 because of retiming purposes.
For more information about device level signals (pull-up/down resistors, buffer type, multiplexing and others), see tables Pin Attributes and Pin Multiplexing in the device-specific Datasheet.
Table 12-4125 shows the use of address and data GPMC pins based on the type of external device.
GPMC Pin | Multiplexed Address Data 16-Bit Device | non-multiplexed Address Data 16-Bit Device (incomplete 28-bit address range) | non-multiplexed Address Data 8-Bit Device (incomplete 28-bit address range) | 16-Bit NAND Device | 8-Bit NAND Device |
---|---|---|---|---|---|
GPMC0_A[22] | Not used | A22 | A22 | Not used | Not used |
GPMC0_A[21] | Not used | A21 | A21 | Not used | Not used |
GPMC0_A[20] | Not used | A20 | A20 | Not used | Not used |
GPMC0_A[19] | Not used | A19 | A19 | Not used | Not used |
GPMC0_A[18] | Not used | A18 | A18 | Not used | Not used |
GPMC0_A[17] | Not used | A17 | A17 | Not used | Not used |
GPMC0_A[16] | Not used | A16 | A16 | Not used | Not used |
GPMC0_A[15] | Not used | A15 | A15 | Not used | Not used |
GPMC0_A[14] | Not used | A14 | A14 | Not used | Not used |
GPMC0_A[13] | Not used | A13 | A13 | Not used | Not used |
GPMC0_A[12] | Not used | A12 | A12 | Not used | Not used |
GPMC0_A[11] | Not used | A11 | A11 | Not used | Not used |
GPMC0_A[10] | A26 | A10 | A10 | Not used | Not used |
GPMC0_A[9] | A25 | A9 | A9 | Not used | Not used |
GPMC0_A[8] | A24 | A8 | A8 | Not used | Not used |
GPMC0_A[7] | A23 | A7 | A7 | Not used | Not used |
GPMC0_A[6] | A22 | A6 | A6 | Not used | Not used |
GPMC0_A[5] | A21 | A5 | A5 | Not used | Not used |
GPMC0_A[4] | A20 | A4 | A4 | Not used | Not used |
GPMC0_A[3] | A19 | A3 | A3 | Not used | Not used |
GPMC0_A[2] | A18 | A2 | A2 | Not used | Not used |
GPMC0_A[1] | A17 | A1 | A1 | Not used | Not used |
GPMC0_A[0](1) | A0 - Not used | Not used | A0 | Not used | Not used |
GPMC0_AD[15] | A16/D15 | D15 | Not used | D15 | Not used |
GPMC0_AD[14] | A15/D14 | D14 | Not used | D14 | Not used |
GPMC0_AD[13] | A14/D13 | D13 | Not used | D13 | Not used |
GPMC0_AD[12] | A13/D12 | D12 | Not used | D12 | Not used |
GPMC0_AD[11] | A12/D11 | D11 | Not used | D11 | Not used |
GPMC0_AD[10] | A11/D10 | D10 | Not used | D10 | Not used |
GPMC0_AD[9] | A10/D9 | D9 | Not used | D9 | Not used |
GPMC0_AD[8] | A9/D8 | D8 | Not used | D8 | Not used |
GPMC0_AD[7] | A8/D7 | D7 | D7 | D7 | D7 |
GPMC0_AD[6] | A7/D6 | D6 | D6 | D6 | D6 |
GPMC0_AD[5] | A6/D5 | D5 | D5 | D5 | D5 |
GPMC0_AD[4] | A5/D4 | D4 | D4 | D4 | D4 |
GPMC0_AD[3] | A4/D3 | D3 | D3 | D3 | D3 |
GPMC0_AD[2] | A3/D2 | D2 | D2 | D2 | D2 |
GPMC0_AD[1] | A2/D1 | D1 | D1 | D1 | D1 |
GPMC0_AD[0] | A1/D0 | D0 | D0 | D0 | D0 |
With all device types, the GPMC does not drive unnecessary address lines. They stay at their reset value of 0x0.
Address mapping supports address/data-multiplexed 16-bit-wide devices: